I got hold off many many years ago a Olympus Zuiko Mirror F8 and the OM to 43 adaptor, when I had E-1. The moon was always something I tried to photograph - yet failed.
Excellent results. I futzed about with a Sigma 50-500 a while back, still hadn't dialed in my GH2 properly and results were on the noisy side. Makes me consider trying again sometime (maybe with ETC and a 2x TC... ~5200mm?)