Need to see the receiver markings on the L/H side. The last 4 digits of the receiver serial number will also be stamped on the side of the rear sight base. I believe it’s a model “392 big S”, which was a post ban 392, ie thumbhole stocked 392. The “big S” stamped in different font after the 392 designated post ban. The model 392 was an ARM with 16” barrel with 1/12 twist for the 55gr m193 and no bayonet lug. There were a very few of those that had a thumbhole stock and if I recall no bipod installed, vaguely recall it was in the box separate. Can’t remember if the barrel was not threaded or had a thread protector tack welded over the threads. Think what had happened was some of the regular model 392 hadn’t cleared US Customs or were on a boat enroute to the US when the 1989AWB had been signed and went into effect. They were converted to thumbhole stock configuration. It would have been an Action Arms. Don’t think Springfield Armory brought in any at the very end like that after Action Arms stopped. Hypothetically speaking, if it’s an IMI/Action Arms original gun and not an “IMI receiver” that was assembled, you could find a thumbhole stock to put it back in its import configuration. Locating a folding stock assembly, bipod and flash hider aren’t difficult either.