I'll guess circa 1954. Always wanted one of those! 

I have that exact same item.  My Mr. & Mrs. Roto-Broil book is dated 1955.

That one appears to have been used as a cook top almost exclusively, considering that the skewers look brand new.

I didn't realize these units came with the detachable tray handle.  I never knew what that thing kicking around in a drawer at my parents' house was for, so I never claimed it.  It likely disappeared forever at the 2008 estate sale.

The heat control buttons have retained their original color.  Mine have faded, and on the one I used to have, they had lost all color.  I have not seen an original blue "Bake" function button since I was a kid, and until now had begun to think I was imagining things.   Keep that unit covered!

Here's why I love mine so much:

Is that temp. dial original? Seems a bit over scaled.

Louie, do you mean the timer dial?  It's original.  It probably was sized for the TOL model, but was used on most if not all of the others as well.

Yep, that's right Ralph. I didn't know there were senior models for this appliance. Then it would \make sense as a cost saving measure.  Thanks!

There were a few models:

Riviera 400

King Size Riviera

Custom 400

400 Capri

The King Size Riviera and the Capri both had "wrap around" lids, and the Capri featured a "restaurant type grill" on top.  The Capri is pictured on the front of the Mr. & Mrs. Roto-Broil cookbook shown above.  The Custom and Riviera models are pictured on the back.

Here's a picture of what I presume is a later model, never/barely used Riviera I found at Savers a few years ago and snagged for Nate (controls are on the side).  The shorter glass panel supposedly improved the roasting process.  You can't make it out in the picture, but the term "Bakes" is missing from the Riviera's list of capabilities across the bottom of the glass, thus ruining the rhyming sequence found on the windows of other models.

I think the baking function was a flop in general.  It required the purchase of an optional "Bake-A-Tray" which appeared to be a heating surface that sat on the bottom of the cavity.  I've never seen one so don't even know how they worked, since the roaster doesn't have a thermostat.  I presume they plugged into the outlet below the "Bake" button.

The average consumer didn't have room for one of these units to live on their kitchen counter.  When I was a kid, the Roto-Broil was only hauled out once in a while to roast a chicken.  I've done a pork roast on one and it did a good job, and it also performed well with two game hens.  I have a back-to-back four-pronged skewer to connect a couple of hens together on the spit.  I don't know if it came with the unit or if my dad, who was a machinist at the time, made it for that sort of application.

Oh for sure, Paul, I would ditch my Roto-Broil in an instant if I found one of those GE's.   Your description of the cooking process is spot-on.  Cocktails and snacks while the appliances take care of things.

Nate replaced the Riviera I found for him (pictured above) with a GE like yours that he found after moving to Tucson, and when I saw it I could tell that it was superior to the Roto-Broil.  Unfortunately, the swamp cooler at his place created such a high level of humidity that the GE suffered some serious deterioration and I'm unsure of its viability these days.

Ken, I'll check the details on the Bake-a-Tray, but I know for sure that it was used inside the cavity, not under the lid.  The area under the lid could be used for cooking, but on the Roto-Broils I've seen, it has always been an uneven surface so saucepans don't make full contact with it.  I think the Capri models were better in that regard, with their "restaurant type grill" on top.

Here's a shot of the Bak-A-Tray instructions from literature for a Capri model that I found at an estate sale. 

The tray came with its own sub-accessory, a combination skillet/deep fryer that sat directly on top of the tray.

In case the fine print isn't clear enough, a "spit closure" insert is provided for use when baking.  The copy states that on the Capri model, the tray will plug into a mystery receptacle when pushed to the rear of the cavity.  Even in the Mr. & Mrs. Roto-Broil Cookbook the copy is the same and there is no mention of how the Bak-A-Tray gets connected to power on the Custom and Riviera models.  Perhaps the tray came with a cord that ran from the timed outlet to the mystery spot on the back wall of the cavity.

I can't imagine doing any serious baking with this attachment. 

One thing is clear:  Roto-Broil's marketing concept that its counter-top appliance could compete with a full sized range was entirely delusional. 

I line the "tree tray" with foil (see picture above) so that item doesn't even need to be washed.  I wipe the interior down with a sudsy sponge and that's usually enough to remove spatters, then go over it again with the sponge just dampened with plain water.  The tricky area is the open nichrome wire heating coils.  You can't really do much up there.

The front glass is removable, and that gets hand washed.  I've run it through various dishwashers we've owned, but none have been able to get the grease spatters entirely removed.  

The spit isn't a big deal to wash by hand.  I put the skewers in the dishwasher if I'm going to run it that same night.

The recipe book says to use a 3.5 - 4 pound bird.  I always buy a minimum 5-pound bird.  They shrink when they cook, and there's no sign of stress on the motor or mechanism.  It even handled one that was pushing six pounds, but I try to stay within the 5 to 5.5 pound range. 

The gears are a little sloppy, so getting the bird properly trussed and well-balanced on the spit is the key to evenly cooked skin, otherwise you'll get some less done areas where rotation falls forward, and blackened areas where rotation falls behind and the spit momentarily stops as the gears catch up.  Balancing the bird on the spit can often take several tries.  I twirl the spit by hand to get a feel for which side is heavier than the other, and reposition skewers accordingly.  It's trial and error but worth spending the time.   Perfect balance isn't likely, but as the bird cooks it becomes lighter, and the rotation becomes smoother.

For me, the finished product is well worth the trouble.  I'm not a fan of white meat.  It's usually way too dry.  That's not the case when it's done in the Roto-Broil.  The breast is tender and juicy, the way it's supposed to be, and I'm fine with letting Dave have the dark meat.