Good pics coop. One way I have been able to discern, if in fact it is a 1976
DDO aside from the massively large devices on 001 and 002, is that on WDDO-001 and 002 I look at the L and I in LIBERTY. Notice how the bottom leg (horizontal leg) of the L appears to "push into" the letter I directly next to it creating what appears as a concave area on the bottom left of the I. Just a tid bit of advice on these two varieties to better help recognize them. As far as WDDO-003..... I don't have such a readily noticeably method. 003 is a bit more difficult to recognize.