The AC of my 300SE (1989) is not working like is should.
Five years ago it was converted to R134 by an AC shop, they replaced the compressor, receiver/dryer, valves and hose.

Last year I replaced the condenser and it worked fine.
Now the temp fluctuates between 60 and 47.

Before I return to the AC shop for my yearly contribution (until now AC repairs cost me more than my DIY maintenance and repairs) I would like an (expert) guess of what could be wrong.

Rob