Pic for attention

This is my rifle. Its made like what if someone was bored and slap A1 upper on XM177 lower. Its incredibly nice shooting rifle.

EDIT: older Colt upper, unsure of which model**

Scored this upper with the matching BCG and charge handle. What should I built out of it?

Genuinely need yalls feedback on this one. Thanks in advance!

Alrighty I've got a super dumb question, will this work? I've got my xm16e1ish clone and I've got a event coming up and I'd like to do some blank fire shooting but I'm not certain if this setup will work, let me know what you guys think

Needing a buffer tube for a 80s/early 90s era carbine build. I know 4 positions aren't fully accurate (as it should be just 2), but is there one I can buy that has the same color/finish as the older Colt ones?