Anyone?....
I'm trying to do the same... I have two separate successful builds: a vibracaster and a boobtube (variant of valvecaster) already, so I'm about to try the grafting procedure. I'm trying to get my head around the possible switching to provide clean boost (V1), clean boost (V1) + tremolo, clean boost (V1) + dirty overdrive (V2), clean boost (V1) + trem + dirty overdrive (V2)... Will update when I come up with some ideas!
BTW I built both tube circuits as P-to-P right on the back of the socket. Tight, but works well.
Here's a shot of my work in progress. From left: the boobtube with only Gain Pot connected; MAX1044 powered charge pump (I'm using the 40V tap); The vibracaster LFO board with LED addition; Vibracaster tube portion. Ins and Outs are not fully finished - I'm planning the switching and wiring to actually be neat so I'm holding off until I get it straight!
https://www.dropbox.com/s/0cac56q08vjulwi/WIP.jpg