I think it depends on what you're used to. If you're used to old vehicles with essentially no suspension it would be no big deal if you looked at the expedition as an adventure and took lots of tools and smiled every time something broke.
My first car was a 1954 3/4-ton chevy truck with stuck king pins, and so it was a real bugger to keep in a lane. Ridiculous in hindsight, but it sure did make driving any other vehicle a breeze in comparison.
If I needed the parts and had time to make an adventure out of it, I'd do it in a skinny minute. That's the stuff that makes for an interesting life. That, however, is probably not a practical viewpoint, and may not be what you're looking for. It also seems by other's responses that you may already be finding the parts you need without having to embark on too much of an adventure.
Have fun in any case -- that's why most of us mess with these old things anyways.
-Dan
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1976 w115 300D 4-speed conversion!!

1985 w123 300TD 4-speed conversion!!
Non-Mercedes old stuff:
1941 Buick Special (Straight 8!)
1946 Luscombe 8a
1947 Willys CJ2a
1950 Chevrolet 4400 dump truck
1954 Chevrolet 3600 3/4 ton
1954 Cessna 195B
1955 John Deere model 40
1991 Ford Taurus SHO
2013 Jetta SportWagen TDI 6-speed (I sold out...