As far as I know there was never a "stock" air conditioner for a 122.
In fact on my 69 164 I'm pretty sure the AC was a dealer-installed option and
it did not look very stock, even though it said "VOLVO" on it. Had to take the
face off it to get to the fuse box, for example.
My first 122 had the evaporator and fan under the rear window shelf and transparent
plastic ducts that blew the air forward in the (4 door) car. It was actually
pretty effective. It got a little additional heat exchange by running the high
pressure line inside the low-pressure (return) line. But the location of the
laid-over compressor caused me to cross-thread #1 spark plug early in its career
with me. It was the best 122 A/C I have had - in a 1963 model.

I think when I reconstruct the AC in one of my wagons I'll get a Sanden compressor
and a really big condensor in front and bigger fans in the inside unit. How it will
fit may be an interesting problem....
--
George Downs, Bartlesville, Heart of the USA!