Well, a 4506 ambi will work fine. Your going to have to piece it
together as there is not one source for all, or a complete 1-5
assembly. (Combination of Midway and Numrich).
Many of my second gen's were missing the right lever and
screw, so I got the price down if I could, and put 3rd gen
safeties on. Most of my second gen's I just changed them
out anyway. I kept all original parts, and am always looking
for levers and screws.