"...barrel blank from any one of the main barrel manufacturers..." Yep. No marks on it at all? That is unusual as most of the aftermarket barrel makers want everybody to know who made it. You can't tell anything by the dimensions though.
Isn't "sleeved for 30-06" though. It was threaded to fit the receiver. Using a Japaneseicon receiver is unusual too.
"...wood filling up into the magazine well..." That's unusual too. I'd bet the rifle was built by some guy who apparently knew what he was doing.