Good Point Loren, and in reality a real good possibility.

However, I believe even if the old bolts were re-used it couldn't /
wouldn't hurt to
check the torque of the bolts after a couple of heat cycles in a newly
rebuilt engine.

Your gonna find out a couple of things;

(A) If the guy that did the engine didn't forget to torque the heads
down properly

(B) If after a couple of heat cycles the head bolt torque is still on
the money.

I would surely highly recommend taking an hour or two to do this menial
task now, rather than replacing failed head seal's later on down the
road.

Just thinking that this is a good idea, even to periodically check a
bone stock un re-built engine.

It can't hurt.

I'll tell ya right up front.
Removing exhaust systems, hoses, and head seals isn't one of my most
favorite jobs on a Vanagon.