Have the top mounted OFH on my coupe also. Sure makes oil changing a whole lot easier. Believe the top mounted housings were equipped on all non-oil cooler 6 series cars or possibly 5 series as well. Don't think the different housing from the later E34's as pictured will work.
I changed from the original bottom bolt filter housings to the top bolt housings used from about 1975 on, figuring they would be less likely to leak. I have removed the whole housing to do filter changes for many years. Current list price for the gasket (p/n 11 42 1 730 264) is $2.87 - insignificant.More questions for Bert...When I did a search I believe you said you would pull the can from the block to do the filter change (makes good sense) and had a hand full of extra gaskets. How do these compare as to the M6 can? I also see you have the 3.5 block. Mine is 3.3 Have you changed blocks since your post back in '06? The can in your picture looks the same as mine (only a lot cleaner!)