Without better pictures, it's impossible to properly decode these. Here are the possibilities:

Washer: A700/A700S

Dryer: DG700, DG701

The washer is a small capacity machine, so take that into consideration. These older pre 1966 washers are a different animal than the post '65 machines that basically remained unchanged through 2006.

The dryer is a halo of heat model and it's getting very difficult to find parts for the gas models. Seals are getting impossible to find now along with gas related parts. The constant burning pilot in these dryers causes the internal metal parts to rust and wiring to slimy junk. The 701 model is a electronic control system which is very nice feature, but extremely hard to find parts for (Timer/Electronic control unit).

If you're looking for a gas dryer to restore, find something in the stream of heat generation from 1976-1979 if you want a center dial dryer. I recommend finding a washer built between 1969-1979 as well.

No where close to a 906.

Look for a 806/808 set

If you like the washer/dryer, and have someone who can legitimately restore them, then get them!  I've not seen a 906 washer or dryer in at least 15 years. They rarely come up for sale.

Here is the electric dryer he had.

That's a DE750. It's basically the previous generation version of a 906 dryer in an older cabinet with a different console (that's a 906 console switch with the incorrect ivory colored buttons....the same switch works on both the 750 and 906 dryers). There are technically 3 matching washers to that 750 dryer: A160/A900/A902. These are all small capacity washers. The 906 washer has a large capacity tub.

I still recommend getting an 806 washer from 1969-1979. It has many more options and much MUCH better flexibility over the 906. Parts are MUCH easier to find! You will absolutely NOT find a timer or water level pressure switch for the 906 if they go bad. You will end up with a useless 225 pound paper weight. There are members here who have been carefully scouring for 906's for decades and are still empty handed. Give up the dream now and stop wasting your time on an inferior washer.

I agree with Dan about the shortcomings of the 906 models, even when they were brand new.  The 806 models were far more popular and are infinitely easier to come by.  You won't regret holding out for an 806/808 model.

Hi Wendy, don't overlook a nice pair of Lady Kenmores or even TOL Whirlpools, WP-KM sold 5 times more washers and dryers than MT and LKs sold more than 10 times the number of machines than MT 806s.

The WP built machines are much easier to find parts and WP washers are  better performers and WP built dryers are always superior MT and really all other US Dryers.

John L.