Yeah, I've been SLOWLY piecing together an AC15 project.  But it's got the Vib/Trem channel, and I'm building it on an L-shaped 2-piece chassis with Radiospares tagboards, a la the originals.  I didn't pipe up because my project is somewhat different from what you requested.
Info on the Vox amplifiers is hard to come by.  It's not strictly an amp builders' board, but what little Vox tech talk there is out there seems to occur at Plexi Palace.  
http://vintageamps.com/plexiboard/index ... b0466d70a3
The AC15 and AC30/4 layouts that I have were given to me as "FOR YOUR EYES ONLY", which I hate, 'cause I think that stuff should be out there the way the documentation for the Marshall 18 has been done.  Instead, the guys who have been doing Vox builds seem to play their cards close to their chest and keep what they've found as proprietary information.  So I'm unable to share much about the Vox layouts, apart from what you can see in photos (which I have plenty to share...).  I'd love to see an online community get together and dissect the Vox line of amps the way the 18-watt community did, and document it.
If you're doing an amp without the Vib/Trem channel, which takes up about 2/3rds of the real estate in an AC15 or AC30, then what's left is a rather simple build I would think, and would fit in a standard Marshall 18-watt or "36-Watt" chassis.  Or you could start with the Matchless DC30 layout at 
www.ceriatone.com and change some component values to make it the same as a Vox circuit.