"Well, others here may have be
"Well, others here may have better info on older models than me but, as far as I know, you can take the model number off of the frame (not the engine block, which is another number)and take that to a Honda dealer and he should be able to order your parts and tell you what "B" you have.
Your thoughts about valve adjustment and replacing the thermostat are good ones and I would encourage you to do both.
Almost everyone on this site would probably steer you away from the Seloc manual and suggest that you get the Helm Publication Honda manual for your engine if you intend to do your own work. It is a bit more expensive but well worth it in my opinion. You can google Helm Inc. and navigate to their order form once you know which model you have.
To Robert A. Fierro...Amen Brother!"