Projectiles look correct. I've shot tons of the incediary and some have had a dual crimp ring. Those are probably reloads. There were a few companies in the 70-80 that sold them. There are still a few. I'd shoot them no worry.
Can confirm that there were 30 cal projectiles with that marking that were incendiary. I believe they were originally in aircraft ordnance but could be wrong there. Only ever seen the pulled bullets or hand loaded. Think they were around 130 gr.