[x33rs]

I should have explained that better.

In the case of this COPO, that tag probably doesn't make or break it for me, since COPO's didn't really have a special tag that denotes COPO. They were either X11 or X44, for style trim or not, like any other base camaro. No big deal to me. It's other clues like having a factory ZL2 firewall piercing, factory muncie piercing, disc brake setup and other small clues. A selling dealer known for selling them is a plus, especially if the vin fits within a known grouping. If you're lucky maybe a BE rear that's dated to the car. But as far as engine and trans, while it would be nice to be original to the car, I wouldn't expect that much 52 years later.
Growing up around COPO's in the 70's and 80's I knew of about a dozen of them, with several close friends owning them (still own them today). They were all over the Cincinnati area and they weren't even that old at the time. Only 1 of them had the original engine and still does to this day. Most of them were run hard and put away wet.

The tags you really see fooled with a bunch are X code Z/28's. Probably X code SS camaros a close second. So many of these cloned now I'm just excited anymore when I see a real tag on a camaro that hasn't been removed and growing less concerned with what engine might be in it.