This should be an Imbel Type 3 receiver. Quite a number of people imported Imbels. At least two that I know of used the name "XFAL". Hesse and Pars International. Your ser# is a Pars. These were imported in 1997. I have a few in the BZ103xx sequence. Has this receiver been refinished or heavily painted? This can remove/obscure markings.
Ser# should be on RH side of magwell flange.
On RH aft end should be---"Receiver made by IMBEL-Brazil"
"Pars International Corp,Louisville,KY"
On LH aft side should be "XFAL 7.62X51 C3A"
The last phone # I had for Pars was 502-363-0000. Give them a call and see if the receiver is theirs.