Materials were fine; machining and finish were so so. Understand, this reciever was not shipped as a complete rifle. It was bought as a stripped unit, and whoever bought it either built the rifle himself, or had it built.
This raises the question of 1)when the rifle was built, and 2)what parts were used to build it. The important thing, if I remember correctly, is that all of them were preban, but you need to be able to establish that it was, in fact, built up into a rifle.
If it was built up into a complete piece before the 1994 ban, then it's worth some bucks.
The other question, of what parts were used to build it, is also important. If good quality upper, barrel, and internals were used then it'll probably be a good piece. If shlock junk was used----well, need I say more??