I have 74K on my 92' 400e and a mechanic is telling me I have leaks in the oil filter housing and the CAM seals, along with another two small insignificant leaks. Is this the type of service issues I can expect for this model? Will these seals need replacing in another 75,000 miles?

It is very normal for these to have seeps. We see them often.

I would confirm the oil leaks with a good steam clean and then drive for a hundred miles or so and recheck. Sometimes it can be residual from an oil change.