After considering the amount of work doing the job myself would require, I opted to have the local transmission shop remove the tranny, and replace the B3 clutch pack and seals, along with anything else that needs replacing, in the hope that I'll be able to get another 150-200k miles out of it.

Although he evidently made a mistake about the possibility of adjusting the B3 on 722.3 externally with earlier versions, I still feel confident that he knows what he's doing, and his price -- $750 for r & r'ing the B3, and no more than $1350 for a complete rebuild, if necessary -- was very reasonable.

Of course, you never know what problems may arise, but the fact that his shop is local and has been in business for 20+ years without any BBB complaints gives me a sense of security that he'll stand behind his work for a reasonable period of time -- which is all one can really ask for in these cases.

However, thanks very much for the very helpful responses, as it helped me make a far, more informed decision than I could have made.