I am wanting to build an authentic(ish) Car-15 or Colt 733: like an exact replica with fixed carry handle. While looking at photos I notice that both A1(SP1) and A2 adjustable carry handles were used. Which was the one used on the actual Car-15 or 733. I noticed a lot of people turn there old SP1 into that style of gun so maybe that why it was a SP1 style carry handle. Anyway, who makes those style of upper receivers?