Hi. I'd bet its a standard NM M1A with a bunch of provenance and history.
Have a semi'd, Winchester, M14 with the issue synthetic stock. Find the light weight of the stock increases the muzzle jump. Not the recoil. Cost me $600Cdn when that was a lot of money. Mind you, semi'd M14's have been declared evil up here. 'Once and MG always an MG' too. It's neat, but not as good as my M1 Rifle. No rifle is though. Not even my '03A4, that'll shoot circles around my M1. There's just something an M1 has that no other rifle has.
"...I won't mess with it..." I wouldn't either. You should be able to see the bedding material in the receiver area. A thin line of a different colour than the stock. Worked in the Canadian distributor's shop, long ago. Before there was such a thing as an NM. Standard, Match and Supermatch, only, in those days. Late 70's/early 80's. The Match and Supermatch were factory bedded with no stock cut for the evil parts. M1A's were long dollars vs pay scales then too.
"..."certificate" is from Springfield..." Documentation doesn't get any better than that. It give a date of manufacture? Just curious. Early M1A's were built with milsurp receivers and parts. Before the ATF declared 'Once and MG always an MG'.
"...the thing shoots .5 MOA..." What ammo? Changing the scope when it shoots like that isn't a good idea. That means sighting in again. Not that that will change how it shoots. Scopes don't do that.
"...means having to re-calibrate everything and puts wear on the rifle..." Re-calibrate what? Wear on what rifle part? It's not a big deal, but, and it makes no sense to me, that the action needs a few shots to settle it in the bedded stock.
"...why would a commerical M1A not be a good as..." Daft assumptions that cast receivers are somehow not as good as a forged receiver. Been telling the M1A/M14 receiver 'snobs' that their engine blocks are cast forever.