The question about (M) and (V) in the O-ring list wasn't answered...
'M' stands for 'measured' - the dimensions are not given in the parts lists;
'V' stands for 'Viton' - a more expensive but higher temperatur material than the standard Butyl rubber O-rings. These are only needed in a few locations, but can generally be re-used because they don't seem to deteriorate.
Another point worth making here: many of the O-ring sizes are non-standard. A few are soft conversions from imperial sizes, and I'm currently rebuilding a couple of engines with standard commercial sized O-rings to check if they can be used everywhere (using metric and imperial commercial sizes O-rings). So far, I've been able to substitute, but haven't finished yet.
When I do, I'll publish the 'substitute commercial-sized O-ring list' here as well.
I have managed to successfully substitute the stangely shaped waterpump 'gasket' O-ring with a standard 127mmx3mm O-ring. It fits perfectly and is heald in place and shape by the little tangs in the O-ring groove. One of my waterpumps had a little bit of corrosion on the tangs and they weren't holding, so I used a thin smear of silicone applied with a match in the bottom of the groove to 'glue' the O-ring in place. I pushed the O-ring into the silicone spear and laid a piece of flat steel on top of it while the silicone cured. The waterpump housing could then be handled and installed easily without the O-ring popping out.
Cheers,
Joe