Yeah,shocked your having troubles with a merc of that era,they are bombproof!!!

A good transit would be more reliable but rust like hell.

Only a suggestion but would a decent trailer and something like a maverick/terrano suit your needs better?

That way if a big long haul job comes up then you could always hire a brand new 4x4 to tow it?my trailer has an awesome electric winch and I've never had any issues with what I tow on it.

Might keep you below the radar of the old bill and the taxman if you get my drift?could make you more competitive then as well?and you can operate all year round.