"Ree-Yees" wrote
Would I notice a loss of power when I
take her out today if this was the case?

You may not notice much if it's just enough of a leak to let a little
coolant into a combustion chamber. Engines can lose a remarkable amount of
compression without any noticeable power loss. Compression check on the
cylinders and possibly a pressure test of the cooling system should tell you
what's going on. Leaky head gaskets seldom get better, btw, usually they get
worse at the most inopportune time.