Sometimes one has to be a detective to reconstruct service data or used parts in the various 500 and 550 models. Some sites like motogrid
http://www.motogrid.com/pages/OemParts?aribrand=HOM can help and most of the Honda documents can be consulted online or downloaded. Our Italian brothers cannot be praised enough for this. Check their
Manuali,
Libretti and Parts Lists at
http://www.honda4fun.com/home.html A document I haven't seen so far is the Owners Manual of the CB 550 1976 and ment is the K model. If I'm not mistaken the cover of that booklet is green and has 76 in the right corner below. Does one of you have that booklet? I'm interested to know in particular if changing the front fork oil is described and what amount of fluid is prescribed for that model.
Some owners manuals do describe this (500K1, 550 1973, 550F2), some don't (500 1975, 500/550K3, 550F 1976).
Second question: would you like to upload that owners manual to complete the collection? So far I know, it's the only one missing.