Super interesting to see one from that vintage with A1 sights!
I have a similar vintage M4gery Hbar with A2 upper from Bushmaster and another with the same XM15-E2S lower markings in a Varmint Special Stainless, which I believe I picked up in 2010? These are the last two factory AR’s I’ve kept for myself, and I’m kicking myself for feeling drawn to sell the Varmint, as I just don’t make use of it (A2 stock, 24” 1:9” twist barrel). I put a Bushmaster National Match 2 stage trigger into my M4gery to improve it for occasional, casual Service Rifle matches and to qualify occasionally on the NRA Rifle Instructor CoF - but my eyes are aging quickly and I absolutely abhor iron sights, so I should probably sell that one too, but I can’t bring myself to sell out my last few Bushmaster branded rifles.