Hello All: I had the good fortune to purchase a good quantity of Thompson Early Parts, Magazines and Drums. I need help enlightening me on some of these parts. First lets start with a 1928 actuator. The knob is bright blue and a thin band of checkering. Is this a 1921 converted to a 1928? Next are 3 1921 Actuators, I am pretty sure the two that are alike are original Colt and the third one is visibly different.having a hole in it and looking unfinished Lastly I am told that this silver colored one is a foreign copy Next the Blish locks. 3 look to be colt, one is marked AO and one marked Savage. The unfinished looking one has no markings 1921 Buffers and Pilots- Some Fit Flush into Each Other- Is that because the ones that are not flush are missing the Buffet Pad? Thanks for all your help!!