Before 1988 the notch was about 1/two behind the slide prevent notch. On all Collection 80s since then it has been located at least a full inch or so again to make it much easier to disassemble once the recoil spring plug is just not removed very first. Click on https://colt1911classic23567.vblogetin.com/37370373/what-does-colt-1911-classic-mean