If it was my horn, in that condition, I certainly wouldn't be gluing anything to those palm keys with the mother of peal key touches! FWIW, I've been using those black rubber key risers on all my horns (S through B) and have only ever lost 1. I have both the Selmer and Runyon variety, not that I've noticed any difference. I have way more Selmer ones than Runyon ones due to their availability where I live.
As for the price of the horn Rob, I'm not so sure you overpaid. It's all relative. If you plan to keep the horn for a while, and it plays well for you, than the price wasn't out of line necessarily. The condition is outstanding, and if it is maintained, the value should be as well.
Weltklang horns are a niche market, and any history that you are able to gather on your horn, would, in my mind anyway, assist in maintaining its value down the road. I know I would like to know the history of the vintage sax I buy, and I'm sure I'm not the only one. There's more of us out there with this
affliction.
Eg: When I bought my bass from Paul Coats, he had done research on it, and he was able to trace its history fairly well. His eyes lit up like a Christmas tree when he told me about the bass starting at the University of Oklahoma & ending up at a middle school in Louisiana, and how it was forgotten about for decades before being rediscovered during renovations. Like I said...We're out there...
Take good care of your new baby Rob. I'm looking forward to seeing some pictures.