This is a very simple thing that can lead to more frustration that high expense. Have you been having some weird electrical problems in your older Mercedes? Maybe you have taken the fuse box cover off and wiggled a few fuses and it has solved the problem for a while. You probably noticed corrosion on the tips of the old aluminum fuses. Who ever designed these old fuses did not get a good education in dissimilar metal corrosion... You don't put aluminum up next to copper - add in moisture and heat and expect to not have corrosion problems.
I have a source of brass/copper alloy high quality fuses that do not corrode in the fuse holders. We are changing out all the old aluminum fuses in our customers Mercedes and replacing them with this new type. No more intermittent or weird electrical gremlins!! Give your fuse box a good cleaning and install these fuses for peace of mind. Look for my fuse kit upgrades elsewhere on this site for modesl from the late 50's up to the early 90's.