As was mentioned the FalFiles is the place for information. I have built a few over the years and currently own 3 metric variant FAL's.
From what info you provided, It is a Metric FAL variant built on an Imbel receiver.
Imbel receivers alone are going for over $300.
If the bore is good and it is headspaced properly (easy to fix with another locking shoulder) it is a steal for $650.
Metric magazines and parts for metric rifles are plentiful and readily available from many sources. Prices for parts and mags are very reasonable.
The worst thing about FAL's right now is ammo, surplus has dried up and what is out there is going for almost .50 cents a round.
"Disperse you rebels!, Damn You! Throw down your arms and Disperse!"....British Major Pitcairn at Lexington, April 19th 1775