I recently purchased a 1989 production R6550 rifle - this is the gov't model with the 20" gov't profile barrel and the A2 upper. The rifle is pristine and came in the original box. Furthermore, the guy I bought it from was the original buyer. There is a receipt in the box indicating that the rifle was purchased by him in 1990 from a local gun store in the area. Basically, I am 100% certain that this rifle has never been messed with, let alone shot for more than hundred rounds or so.
I was playing around with it today and realized that the safety will go 360 degrees around as the Colt lowers obviously have the selector stops milled off. I believe that this rifle actually left the factory with an M16 safety installed. It has a regular semi-auto bolt carrier and hammer installed.
I would like to replace this safety with exactly the period correct safety which it should have come with from the factory. Would anyone be able to provide information of how to differentiate such a safety from new production? Would an SP1 takeoff safety be the correct kind, or was there variation in small details of the safety throughout SP1 production?
Finally, I would like to ask if anyone has ever encountered an M16 safety factory installed on a Colt preban rifle. Seems that this would be a big oversight at the factory as the thing can literally swing around full circle in its present configuration.