Hi Trev,
Your statement agrees with what my research has found.
For me I dumbed it down quite alot, my criteria were:
*Easy to buy
*Multigrade
*Ashless dispersant,and,
*designed for use with air cooled engines.
What I've decided on is Phillips 66, 20W50, it meets all of my dumbed down criteria, can be purchased at just about any light aircraft airport at about $7 per Quart ( 950 odd mls ).
How many owners are operating their primary drive chain case dry / with chain lube or dry lube ?.