I have never heard of Franklin Arms, nor has Google. Bushmaster ususally did conversions on Sendra or Frankfort Arsenal receivers.
Things to check for. Make sure magaznes go in/out easily. If possible try putting a std. current production upper on and see if the push pins line up correctly.
Check carefully for any cracks forming. The trigger and hammer pin holes should be round and tight, take off the upper and cock and release slowly by hand the hammer back and forth. Watch the hammer pins, they should not rotate with the hammer, not uncommon that they do but it indicates some hole wear in the receiver holes if they do not remain stationary while the hammer pivots. Check the tabs on the receiver where the trigger guard pivot pin goes through. Some goobers crack these when changing the trigger guard.
10K is about right for any of the Clone guns now. If the receiver is cast and ugly I think you could probably fine a forged no name conversion receiver off the web for similar money.
