I dont know that I really know my stuff, so much as I went through exactly what youre going through when I started building rifles out of old miliary mauser actions a few years back.. I was concerned about max pressure, steel qualities, whether or not an old action built in the 30's that got drug through mud and debris for years and then likely stored in someones attic for the next 40+ years could possibly be accurate or made to look decent after decades of rust, pitting, etc... I was also concerned about the overall quality of a rifle made in Brazil, Argentina, Mexico, China, Singapore, etc over half a century ago (until I realized most of those "foreign" mausers were actually made in German, Czech, or Belgian factories to the exact same standard as BRNO, DWM, FN etc mausers and then just exported to the country whose name the rifle bears...)..
Turns out the best mauser I own (tightest fit, best steel, best overall condition, etc) is a Mauser manufactured for China... its action was used for my .35 Whelen build.. Once I researched a bit, I found that BRNO made a large number of M98 mausers (the VZ24) for China in the mid to late 30's just before the Japanese invaded.. The Chinese stored most of these rifles in warehouses not wanting to issue them because they were new/nice, and they knew they would need them if/when they were ultimately attacked by a foreign power..
The Japanese did in fact invade in July 1937.. and overran China so quickly that almost none of the mausers ever actually made it out of the warehouse.. My "China" VZ24 was made in early 1937 and likely barely made if off the boat before the Japanese took it..
When the Japanese took over the warehouses, they didnt want the mausers either.. they werent chambered in a caliber they could easily use, and they preferred their Arisakas.. so they just locked them up, secured the storage facilities, and sat on them in case they ever needed them..
VZ24's built for China all start with a P in their serial number.. just under 200,000 were exported, and they are considered by many to be the best "pre war" mausers you can buy (well made, almost certainly never actually fielded or used, stored well, etc..)..
As a side note / fun fact.. The Japanese also bought about 40,000 VZ24's from BRNO just prior to WWII kicking off.. but very few of them were ever issued, for the same reason(s) they didnt field the Chinese VZ24's once they were captured.. I think most, if not all of them went to the Japanese Navy.. So if you ever find a Japanese Mauser.. it is also likely very, very good.. (although if still in its original military configuration, and not already sporterized, it is also likely going to be VERY expensive as collectors go nuts over them since they are relatively rare now)..
