Hello Cathleen, welcome to the forum
You might just go ahead and try the Beomaster. There's a very good chance it will just work, the switches and sliders may need some exercise to work cleanly without scratching. Do you have any kind of speakers for it?
The Beogram will most probably need a cleaning and lubrication job and a new belt before working properly. That won't be a big problem if the stylus is still OK - if not, getting a new one will cost a bit. If the stylus is good and the deck worked when you put it into storage, I would again just test it... but don't use your favourite record!
Sorry I can't help you much with service facilities over there, but I understand it can be difficult in the States. The dealers will most probably refuse to work on old equipment, or they will delegate the job to someone else anyway.
Regarding the service manuals - if you decide you will need them, you'd probably do better upgrading your Beoworld membership than buying them off eBay. Silver level costs about the same as a couple of manuals, you'd get access to all we have here, and some of the manuals on sale have been downloaded from here anyway...