The "Chinese" base could be easily milled to duplicate the contour of the original. The Redfield marking is a simple job for a decent engraver. Bead blast and park it and you have it. The one I bought for my SC A3 fits the front ring perfectly. Prussian blue shows perfect contact. It also has 8-40 screws. Perhaps the variations in American wartime "rush em' out" A3 receiver rings was a lot greater than the current Redfield bases ?
The "Chinese" base for 03's fits 1903 (real) Springfields perfectly. The standards for 03s were so much higher than any 03A3, that IMO they provide a far better "read" on the quality of the "Chinese" bases.
As for the fixed Alaskans on 03A4s there is one sitting in the Smithsonian. I have 2 N/A new Alaskans.
Both were made in 52' according to the brochures in the box.
WW II no, Korea or Vietnam possible as A4s were used in both.
If you are counting on Stroebel's book for anything ...... don't. It has more errors than an Obama speech.
BTW the "Chinese" 1891 Mosin 91/30PU was as good if not better than any 330 equipped A4.
Certainly far better optics. ....... ask Whitefeather.