looking into a 1987 300TD wagon. I'm not a big fan of leather, and am curious if there's anyone out there who has swapped out for cloth or other seats. Is this an easy swap, are there any seats out there that will fit nicely in the 300TD?

It should be pretty easy, on several occasions I have swapped seats, in my case I put MBtex in instead of cloth, my car is a W126. You should look for seats out of a low option TE or TD, leather would have been the most expensive seats available. the trick is finding good seats, and the prices.

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1984 Euro 300SDC, (4spd standard)
1986 Toyota Landcruiser Diesel HJ60 5spd X2

Gone but not forgotten (some sold, some stripped)
1983 300 SD, 1985 300 SD, 1983 240D, 1986 300 SDL, 1985 300 SDL, 1983 300 D, 1984 300 D, 1985 300SD, 1987 300 SDL, 1983 300 SD, 1985 300 TD Euro, 1983 380SEC, 1990 300 D, 1987 300D, 1982 300D, 1982 300D, 1994 E420, 1987 300 TD, 1987 300 D, 1984 300 D