Hi Jim,
i agree a difficult decision as you say 50% say do and 50% say don't.
But as you say you want to keep it then i think you have made the right decision to have it done.
I have just thought that my wife has got a Mercedes E Class that had a gearbox problem,she had the gearbox
oil and filter change,all ok for a month then the problem started again.The indy we use stripped the gearbox sent off the gearbox
inner plate for the electronic selector to be changed and all is now well.
I suppose that is another reason why i have come back to an S Type,(less electronics,i know they can be frustrating(see my post on expansion tank issue).
Mine is also going through a rolling recommission,the last owner had it 15years.
Good Luck.
Graham