I would definitely not retro-fit for two good reasons. First York 2 cyl compressors are not suitable for retro fit.
And second and most important an 85 should have a nipondenso compressor which leads me to believe your grey market car has grey A/C (not factory). The SLs never had great A/C but they had the worst of hang on units.
I never like to retro-fit marginal systems. The factory system on 107 SLs approached being marginal, the after markets were worse than marginal. The biggest problem was that you couldn't put the evaporator in the right place without the factory box.
Owner 24 bay BSC
Bosch Master, ASE master L1
26 years MB technician