Mark,
* This late in the war, Walther must have known the Americans were only days away.
* IMHO: I think Walther returned back to "Commercial" production to:
(a) Keep the workers occupied.
(b) Use up the warehoused commercial slides (MOD 38) from earlier days.
(c) Promote an aura of once again being an firm independent of its Army contract...a distancing if you will.
(d) Attempt to generate some income since the Gov't was obviously not going to be a long term solvant customer much longer.
(e) Provide "civilians" a means of defense.
* When the WaA inspectors left a month or so before the end of the war, I think remaining ac45 slides were used. The transporatation of in bound forgings must have dried up. Since these were not an Army order any longer, I think Walther returned back to the concept of a "zero" series and marked these late ac45 zero's accordingly. In this manner, Walther could not be criticized for selling Military configuration equipment as they were marked like a "test" series. And too, they were fully functional as "commercial" sales items.
* Just a SWAG...less the Scientific.
* What do you think?
Bob