OO great guitar!
Just curious, did your 12 string Festival come with a case? A lot of Washburn 12-string guitars have heads that are so long that it is hard to find a case into which the head will fit. If yours has a case, you're very lucky!
Glad to hear it's going to work out. Evenkeel has done a lot of instrument care and mods...so you can certainly follow his advice.
One thing...you mentioned a chicklet saddle? Be careful to look carefully and remember the orientation and location of each of the chicklets...get them reversed or out of order and the intonation will be all messed up.
If you're looking for a bone strap button, you couldn't do better than going through Bob Colosi at www.guitarsaddles.com
He can make you end pins, too...and match your bone strap button to your current endpins if you already have some you like. I use his "West African Hard Ivory" products almost exclusively, but they are expensive and of course you don't dare to take the guitar out of the U.S. or you may not get it through customs on the way back. Things may be a bit different over on your side of the pond, though.