Welcome aboard Len, I've seen where some have had to replace the O ring(s) on these B series and according to what they posted it wasn't too bad. I believe the main problem they encountered was getting the snap ring out.
If you don't already have one a aparts manual would be very benefitial to have. www.messicks.com used to provide an on-line parts manual and www.tractorsmart.com will email you one if you request it.
Also, a WSM would be a great resourse to have if you plan on wrenching your tractor yourself. Unfortunately I don't know of a free source for them so you'll have to purchase one from a dealer. You could check ebay also.
Good luck and let us know