Safir does not build cars, they license the trademark to Superformance. The original Safir Engineering in Byfleet did build cars in the 80s-90s when Peter Thorpe ran it. Peter sold the name and trademarks to the US company that is now Safir.
Safir have built one car- mine- they took the David Brown chassis I sent them, had the body made from their molds, assembled the body to the chassis, and they also built the suspension, the shift linkage for the ZF transaxle, supplied the steering rack and various other bits, and so on. The assembly and machining part of Safir GT40 is Brady Pack, who is a very good machinist and engineer as well as a car nut. My car carries (or will carry, once we get around to putting a builders' plate on it) a serial number which was given to it by Safir. They also were instrumental in having my car included in the Shelby Registry book which came out a year or two ago.
It is possible that they have built other cars as well; I know they supplied replacement chassis for at least one car which was damaged in a track accident, maybe more than one. They are certainly capable of building a car from the ground up.