OK, I'll take a stab at answering your question.  I note that you hail from Canada, so if you grew up there, keep in mind that you may be accustomed to seeing slightly different products that I'm used to seeing here in the states.  But, based on your description I would venture a guess that the machine you're describing was a post-1963 product; probably a '64 or '65.  The console you describe was probably the same as in this photo, although this is a much newer Filter-Flo.  The console shape, layout, template, stamping, whatever was introduced in 1964 by GE.  Prior to that the consoles had a vertical face (not inclined as this one is), the toggle switches operated in an up/down manner, and I am not aware of any rotary switches prior to 1964.  In 1964 this console was introduced and featured toggle switches that now work in a left/right manner (2, 3, or 4 switches stacked on the left side of the panel), sometimes with a chrome rotary-dial-switch that could control water level, or an optional feature such as second rinse (or not) or suds return (or not).  The trim at the end of the console varied between two designs, one of them featured a "flair" at the top, as the trim in this photo shows (that's as close as I can imagine anything close to your "inverted L" profile.  Someone on here acquired (within the past year, I'm thinking) a basic Filter-Flo from the mid 60's that might illustrate the design you're describing, but I can't find the pictures.

Anyway, this might serve to launch a discussion and even photos that might come closer to the answer you're seeking.

Lawrence

If you will look back to Thread 35998 (I think I've got that right...) you'll see the 1962 Filter-Flo that our Webmaster recently acquired.  This console is typical of pre-1964 models.

L

Here's a great old 1963 model owned by Mark in Virginia. Fits a lot of points in your descriptions especially the color of the panel and the big toothy toggleswitches. There's a chrome knob in the center, but it doesn't have anything to do with the suds saver. That's controlled by the double-wide white toggle to the left. Gorgeous machine. One of my all-time favorite Flo's. Lighted control panel. Even has a primordial mini basket and what GE described as a "one-shot bleach dispenser".

Yeah, that's what I figured if the '63 example wasn't it. That model is about a 1967, the year GE decided that its 12 lb capacity machine wasn't really a 14 lb. capacity machine, it was, in actuality, a 16 lb. capacity machine (16 lbs. of mixed soaking-wet fabrics); Gansky has a pair. What you're remembering as battleship grey was really a very light tint of blue. The suds saver knob would have been an option and would have been placed in the center of the panel next to the "load select" knob if there was one. These machines, in the US,  usually had a black activator with a green cap and a filter-pan that could have been such a light tint of green that it read white. I've seen Canadian examples of these where the colors were different. I think this machine belongs to Swestoyz.