Honestly this is a very easy repair. It would just take some time to source a proper ground glass.
I can fix it for you or help you DIY. I might even have a suitable piece of ground glass...
Otherwise, I would suggest one of the following:
??? (sorry, I forget the name of the) camera repair place in Oakland near 14th and Broadway. They've been there forever and do pretty decent work.
Keeble and Suchat in Palo Alto. They have a repair counter upstairs with the darkroom stuff. I think they send most of the work out though.
There used to be a guy on Villa street near Castro in Mountain view - but, last I heard, he retired.