I remember doing one a long time ago - a friend wanted an MOKF cover by Gulacy, for his home gym, I did a BIG careful copy, then inked it and coloured it, he was happy with it. I do enjoy drawing my own stuff but it is a different pleasure to copy art you admire, and sometimes more relaxing.
I'm curious though--not sure if I've asked this before--but why do you do, or why are you being commissioned to do so many recreations? Sorry if this is a bad question to ask, but with your skill I'd definitely commission you to do an original!
My clients are original art collectors who don't want to pay five figures for the high end originals I recreate, so they commission me to do a close reproduction at a fraction of the cost. I guess it's the next best thing to owning the original.