If it is from 1948 the prefix to the serial numbers would be FW S and it should have the Single Sighting Plane rib. I think a 20 ga. with 30 inch barrels would be rather rare, and I've also read somewhere that it seems to be the 20 ga. with the 30" barrels are found more in California for some reason. Might have been a Bay area duck gun club special.
If it wasn't ordered with any special chokes, Hunter Arms made them full/full.
I would definitely think that in unused condition it would be worth more than that.
Let us know. I'd love to see some pictures of it.
