Judson: I have not been on this site for years but just now stumbled across it again & here are answers to your questions. Your Wizard Super 10 Model WM7 was the first run built in 1955. This run started with # 826920 & ended with # 830919 & there were 3999 total motors built in that 1st run, built by
Mercury of course, The WM7 & WM7A BOTH carried the Merc Mk 25 powerhead with the larger crankshaft, 4 cage reed block & the SINGLE fuel line, NOT the double line pressure tank as the earlier models. The WM7 indeed had the MK25 fuel pump & should be kept that way & not reverted to the old double line pressure system. They ran the phelon mag & I used the new 50-1 outboard oil & just mixed it 1/2 pt to a gallon which is a excellent mix as I ran mine as a racing motor for many years.The WM7 & WM7A were the last of the Merc built Wizard 10's & the best by far as the MK25 powerhead was much improved & stronger over the older MK20 powerheads. I restored many of them & also raced them & they are a excellent motor & relativly a trouble free running engine. Hope that helps, since 2008 I have switched to & am collecting & running the Martin 200 engines.
Ronald