I think that is Schumacher iron. The choke is so it would make sense, and those aren't Dynaco part numbers. It looks like a late '69 code on the choke, so assuming that it's not a replacement; based on the trannies also being Schumachers, I would guess that it's a 1970 or 1971 amp.
It's unusual that the chassis wouldn't have an inspection date sticker or grease pencil date on it somewhere. Look for EIA codes on the other components such as pots, etc. Somewhere on those trannies there is probably an EIA code also, probably starting with "606".
Sunns are hard to date precisely, EIA code only show when the particular part was manufactured so all you can really tell from them is that the amp was manufactured sometime after the coded part was.
Also Sunn has a lot of anomalies, particularly around the time of the transition to Hartzell it seems ('71). I've got a tube rectified 200S with a 1971 inspection date, as well as a '72 dated 2000S, and both the tube rectifiers and the "200S and "2000S" nomenclatures were history by then according to the catalogs.
I suspect they were using up old parts inventory, but that's just my guess.
Good Luck!
