my name is Marco, I own a TR4A IRS and I have been recommended to this forum by Peter Cobbold, please be gentle with me bacause my simple english.
I owned a MB 230 SLK from 1999 - 2007, long time sold, and used parts from this model are on the market for small money.
The compressor you get for about 200 Euro! There are 2 different types + the AMG 6 cylinder compressor. I take a look for it at eBay from time to time....
Did anyone try to fit one on a 4 cylinder TR? One "problem" is, it runs only with air, on classic cars compressors run with petroled air.