I know of several other factory MG38s, but so far only one original MG38B in the NFRTR. This onion appears to have been parked at some point, and being a commercial contract gun from Colt, it would probably have been blued originally. Colt sold a lot of MG s in all sorts of calibers. Dolf's book probably has the stats on how many went to Argentina.
Dolf and partner, Fred Kasse, had an MG and MG parts business called ARPAC out of CA for quite a few years. I used to get their flyers which had lots of really good vintage parts and every once in a while, there would be some MGs offered. I don't recall which flyers had the ad in the early nineties, 1993 if I recall, but he offered an MG38B with some accessories for $12,500.00! There was a pic in the ad, but the pages were mimeographed so it was mostly a smudge. Quite a temptation, of course, but extreme price. Someone bought it.......Trashed out registeredMG08s could be had for $800 and C+R 1917A1s for $3k and less.