Need help with an old AR-10

[mskdgunman]

A friend of mine's father (and my gunsmith) passed away a while back and while going through his stuff, my friend found a couple items he was curious about. The first is pretty straightforward and is an AR-10 lower receiver made by Specialty Arms, Springfield Ohio. Google has turned up a little bit on the company but I was hoping that some member(s) could shed a little more light on the item. Specifically, when were they made (roughly), are they a good quality part, will current AR-10 parts work in the lower and it's approximate value. Any other information would be welcome.