73 and 74 things were different. 73 had a gas heater, no provisions for heat on it's original fan shroud and no intake covers on either side of the rear quarter panels. If the fan shroud has blocked off air channels for air circulation for heater boxes, make sure to take off money for that, it's not original. If the gas heater isn't working or is missing, take off money for that. The thing also had unique suspension pieces, it uses a type 1 geabox, but uses type 2 cv joints and also it had a vw bus front suspension. Your thing should have reinforcing bars for the front suspension, from the factory and it should have a special sump protection grid assembly consisting of a left and right grid underneath the engine, but clearing the oil strainer as well as a front connecting piece. Can't remember if it had a 4th piece or not. If your thing doesn't have these, subtract money as well. The front suspension reinforcement pieces are easy to get as well as the sump protection pieces. The 73 only fan shroud is hard to get and is a favorite of vw performance and dunebuggy enthusiasts. Gas heater parts can vary and are available, but seem to be hit or miss on thier availability.
Nicholson 500x (Project)
Nicholson 185s
Nicholson 110 (That takes an atc70 tank)
Ascott 500 head/350x (Project)
Homebuilt Racer Chromoly Suspension 110 (Ragin Runt)
PK Racing Suspension 70
A+ Inc Suspension 70
AWS Aluminum 90 frame
Hi Performance ATC Suspension frame rd350
Hi Performance ATC Suspension frame 90