I got one: Original piston drive 5.56mm Armalite AR-180 (Sterling)

[jmoore]

Nice rifles! Done went and sold my Costa Mesa rifle to buy something else, though.

ETA: I did ruin whatever collector's value it had by modifying the mag catch and mag well to accept M16 magazines as is. (Made a form block insert to drive into the magwell to create clearance for the raised area on the magazines just below the catch hole.)

Odd how this design was so overlooked as a whole, but quite copied/adapted in individual or groups of features.

Copycats in whole or part:
FN FNC
Australian Leader Dynamics T2 MK5
H&K G36
Gas piston AR15s
FN SCAR-L (Mk16)
"ACR"