If anyone is interested I bought a R12 vacuum and recovery machine for removing and adding R12 and no longer have that bus.

If someone wants it let me know.

I too had my OTR AC repaired and stayed with R12. It was inop for who knows how long when I got it and once sealed up needed no Freon afterward right through the sale.

For the record 134A is harder to contain than R12 the molecules r much smaller in 134a hence the 134a lines require O-rings where the r12 lines never had.