[DonVoigt]

Side plate may have an "8", but it is not original DWM manufacture.
By serial 8008, production was well established.

Your example has been significantly buffed and refinished, probably removed a few numbers.
The original side plate would have had a number along the bottom edge.
The take down lever should have a number on the bottom also.
The mid toggle link may have a number on the bottom inside, the breech block should also have a number; the number on the rear of the toggle may have been polished away- but I think I can still see residual numbers there.