General Shaver was a division of Rem Rand and they are about the scarcest WWII mags. In addition to the usually faint "G" struck on top of the toe, they are unique for the period in having a welded seam down the spine. A third series R-R 1911A1 as this one is, would have been shipped with Risdon, Little, or basically any mags not manufactured by Colt or having a "C" prefix. In terms of restoring GI 1911A1's, parts correct for a R-R are about the least expensive and easiest to find and slides on these did not have numbers matching to the frame as would be the case with Colt during 1943 which would be the production year of the pistol in question. That was also the year that High Standard began barrel deliveries. Later R-R's would have Flannery Bolt (F) barrels but an early third would typically have been shipped with a High Standard barrel. 1st and 2nd model R-Rs frequently have pre-war Springfield barrels and even occasionally Colt with some other Colt parts.