Early to mid 60's
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.