heres some info on Browning Model 12/42 dates straight from my stash of orig Browning catalogs;
1989: Model 12 in 20g introduced - 8000 GrI models and 4000 GrV's to be made
1990: Model 12 in 20g still catalog item
: Model 12 in 28g introduced - 8000 GrI models and 4000 GrV's to be made
1991: Model 12 in 20g no longer catalog item
: Model 12 in 28g still catalog item
1992: Model 42 in 410 introduced - 6000 GrI models and 6000 GrV's to me made
: Model 12 in 28g still catalog item (interesting to note in the "92 catalog is says 7000 GrI's and 5000 GrV's to be made vs the original claim of 8000/4000)
1993: Model 42 in 410 still catalog item (last year, not in '94 catalog)
:Model 12 in 28g no longer catalog item
I have read before that many of these guns sat on shelves unsold for quite some time after, so it was still very possible to get these new from dealers even into the 2000's. I myself (a former owner of many of these fine M12 repro's) remember a few dealers still having some mid 2000's