Back to the original question, as modified, there was no bayonet for these BM59 copies.
Edited to add more info.
You can read more on this site:
http://ww w.machinegunboards.com/forums/index.php?showtopic=5033
From that website:
"US Built Variations:
In 1964, Golden State Arms, Pasadena, CA, began offering the "Santa Fe" BM59, or "M59". While most, if not all of these were built around re-welded receivers using the 03 barrels, they did obtain licensing from Beretta to manufacture them. You will see these rifles either with the Beretta Licensing agreement, or without it. Although marked with the Beretta licensing information on the left hand side of the receiver, the buyer should still remain aware that these were built in Pasadena, CA., and NOT at the Beretta factory in Italy. At this point, I am unclear as to why some of the Santa Fe Arms rifles are marked with the Beretta License Agreement, and some are not. I think that it is quite possible some of the earliest are not marked, and that the later ones are not so marked, possibly because Beretta was not happy with the quality, as indicated by a few writers. One additional note about the Golden State/Santa Fe, I have heard one reputable gunsmith say that some of these were actually imported. I have seen photos of an M1
Garand that was marked with Santa Fe/Golden State markings that I believe most probably was an import, but never have I seen a Golden State BM59 that I believe was an import. Most probably, any Golden State/Santa Fe you see will be a re-weld. Re-welds were also built by National Ordinance and Federal Ordinance.
One important side note to the Golden State, and similar versions, is they use a simplified front magazine catch that is not standard Beretta design. Replacement parts for this catch are unavailable, and I have seen a few people looking for them. I don't know of anyone who can provide these. Perhaps in the future, I will have some machined up for those who need them.