I think Barrett can use the rear torsion tube and horns, retaining the S/N from a donor VW, if I'm not mistaken. During the last days of Thunder Ranch, this is what they were doing. Those cars had a nice, wide (if a bit high) seating area-- something that can accept better and more comfortable seats than an early IM/CMC or Vintage/JPS.
The further down the road I get, the more I think this "hybrid" approach might not be such a bad way to go, assuming some sort of better front suspension could be adapted. There's nothing wrong with the rear end of an IRS Beetle that couldn't be cured with some relocated trailing arms and a set of coil-overs (or with narrowed trailing arms and torsion bars)-- and adapting an A-arm front would not require a Mendeola setup, as long as you weren't dealing with a Napoleon's hat (and you wouldn't be with a fabricated frame). I'd jettison everything in front of the access plate, and build a frame from there using a ubiquitous Mustang 2 style front end.
Doing it right would eliminate the need for a traditional early IM/CMC/Vintage subframe of any kind-- the outboard rails on the pan-replacement frame could just grow, and everything (including some of the steel generally used in the subframe) could hang off them. The body could be bonded into this steel for a nice, tight setup with zero duplication for frame members.
This, coupled with wider mounting points for the front end would allow the cabin and footwell width to grow as wide as those in a Beck or tube-frame IM.
Guys in states with tough replica laws could still register them as VWs, and guys in SEMA states could use the MSO for the bodies to register them as a '57 (or whatever) replica. It'd be win/win.
It's a thought, anyhow.