Aren't the 750's headers double-walled? If so, there would be really no way to repair the dents. On my '79 CB650 and '79 CM400T the chrome part of the headers is just "decoration" and the real pipes are about 1/8th inch smaller diameter. At the cylinder head the diameter gradually decreases before the first bend of the pipe. On a side-note, this could be why Mac/aftermarket pipes got the reputation of losing torque compared to stock; if they're not double-walled they're going to have a larger ID and therefore will produce less exhaust gas velocity which directly correlates to low-speed power production.
I personally like the look of blacked-out wrapped headers. The original idea of wrap was to keep EGT's constant through the pipes which increases inertial cylinder filling.
