After a long hiatus, took a few days off to get things done outside as it is actually cool enough to do so most of the time.
The under-dash AC bit has worked well and has not fallen off, etc, and has provided excellent service as a heat blower recirculating hot air from the BN4 around the cabin.
Finally got an AC compressor mounted, this one is a automatic variable displacement V7 Harrison//Delphi unit off a `2010 HHR with <10K miles. Centerline was setup ~same as the York compressor setup, fan housing is vanagon, used only the to-fanhousing plate of the factory Vanagon compressor mount.
This compressor is actually much smaller in the significant dimensions that the Sanden I have off an 05 Neon, and you can get a Vbelt pulley setup for it, as well as a reverse direction clutch (still need that---the compressor doesn't care about spin direction, but the clutch apparently does)
The only real issue I have run into is the saggy old Vanagon outer motor mounts, going to do a tiny bit of clearancing for the belt around the crank pulley (modified from a Dorman steel PS pump pulley for a Ford) serp belt worked out to be a std unit stocked at my local FLAPS.
(plus the modded PS pump crank pulley is significantly larger than the factory v-belt unit)
EDIT: Looks like they will work for now, also did a bit of grinding/sanding on the oil cooler side fan housing bosses and mating bosses on the fan housing to ensure belt clearance.
Looked at putting the original oil cooler in... It's so close...
Belt is a 4N438, could bet away with a 5 rib but might have to fiddle with the pulley offset.
I'm going to have to box the air channel in the body a bit for clearance for the AC lines, but not too bad.
It's almost in the realm of a couple whacks with a hammer, depending on the line setup.
I'll add a picture of the compressor mount by itself later, currently adding ~3/8" spacers (AKA nuts) under the T4 inner mounts to raise the compressor pulley to a safer height off the crossbar--- tubular framehorns are planned RSN, but this will work for now.