On a few points I beg to differ. I assume you were not in Vietnam in "the war we chose to lose" ? In that conflict A4s were fairly often seen and I never saw one with a 330. K4s, K6s, various Redfields, Navy guys with Kollmorgens for mine shooting and antiship sapper defense.
(from wiki) "After the Korean War, active service (as opposed to drill) use of the M1903 was rare. Still, some M1903A4s remained in sniper use as late as the Vietnam War; and technical manuals for them were printed as late as 1970.[5] The U.S. Navy also continued to carry some stocks of M1903A3s on board ships, for use as anti-mine rifles."

As for the "Chinese" mount, I'll await the metalugical analysis that shows it's pot metal. I guess I'll have to take the one off my 9 pound 400 Whelen Springfield as after 300+ full power loads it will no doubt fall off any day now.
As for test fitting, after leveling up everything, when you clamp a mount down on an action with two big hard wood blocks and two 9" C clamps, there a'int no way it's not on a lot tighter than two 8-40 screws will place it.
As for Alaskans used in combat, there are dozens of photos of troops in combat with Springfields with Alaskans on them and they were even cleaned off the shelves to get something into action as the M82/4 contracts dragged on and the 330 was a POS. Even the Brits experimented with Alaskans in G&H mounts on SMLEs as shown in Skennertonicon's book.

As for Chinese products, I have a friend who builds replica 428 Cobrajet engines. The ONLY country in the world that could build him "dead on spec" exhaust manifolds was China. I'd bet 10 dollars to a dime than an optical scan of 10 the terrible Chinese bases vs 10 various vintage A303s would show the bases are far more dimensionally consistent than the front receiver rings.

Found a highly rated smith in AZ who has done many, many SCs using the welding rod method with complete success. Now it's only a choice of which scope will go on it.