first i'd heard of other mfgrs having salt wood problems, i was told by a dealer - well, it was Richard Kennedy, formerly of the Gun Room in Smyrna, Ga (whom i still consider an unimpeachable source for almost anything; pity he shares the namesake with that bunch up in MA). he named off a pretty good list that included most of the major US mfgrs. i do know i saw an otherwise NIB winchester commemorative lever gun of some flavor once that had the tangs rusted almost half thru. there was no sign of any other damage to indicate that anything outward had happened to the gun or its box. i was puzzled at the time to explain it but salt curing would have caused it easily. i had a very early ruger #1 that had the butt plate screws so rusted the heads broke off and the drawbolt was rusted away to half its original diameter and almost twisted off in removal. this #1 didn't show any signs of rust damage on the action or barrel but all that metal had been teflon plated at some point in the past. also, somewhere and i don't recall where, i'd read that the US Army had the problem from a supplier of M14 stocks but i've no idea where i ran across that tidbit. in short, i've got no "proof" as such, but like i said, he was a pretty reliable source of info.
what he'd told me was the other mfgrs flatly refused to acknowledge the problem at all and Browning got all the bad PR because they did something about it. still, if so, it must not have been as rampant in other brands or we'd see more evidence of it today.
roger