We just made a lens board oddity ourselves: Graphic View to Cambo adapter (lenses are on GV boards, which in turn go into the Cambo board. Hearing the quotes you got, I am mightly glad we can conjure these things up without costs. But mind you, this takes several hours of work, say 4 or 5. And how much are the wages of a skilled woodworker? Somewhere between 50 and 100 per hour. So I don't think Grimes offer is too high in itself, taking into account it is probably a metal construction he would make instead of wood, but it is sure dear if you haven't got the money. I hope for you someone where will step in and offer his/her service to a fellow Apugger if you really can't make it yourself. Or try a Japanese site like Kochi-med where there are plenty of instructive images of DIY camera repair and learn to do it yourself from there on. Sorry that I can't be of more help.
Norm