I've got one out of a 90 td good working order, can sort delivery if needed. 200 delivered for the box and 250 delivered complete with transfer box etc
I wouldn't waste money on wax oyl the best protection for a chassis in that condition is to spray it with old engine oil and diesel mixed it really gets into the dust and rust....as my old man said good oil seals were the death of a many a good car!!
I have an 88 QT 3.9 auto, engine and box just fitted, engine rebuilt, new cam,followers,rebuilt heads, new bowler extended shocker turrets, bowler wings, wildcat bonnet, just needs finishing. £2500
My 3.9 auto 90 developed a misfire I spent days if not weeks trying to sort it,turned out the cheapie tin head gasket had failed a compression test showed nothing but I didn't do a compression leak test that would have shown the fault, on inspection one pot on each bank had leaky h gasket. Mebbe...