Dunno about lincs mate but dont drive it anymore as you will destroy all sorts and add to the bill.

Back in the day (although not local they do a collection service) I used to deal with kidderminster transmissions who would do me a box for about £250.

May be worth a google! Its been years since I used them though but I would imagine they are still about. The boxes arent built to take 1000hp but are a good rebuilt unit to get you up and running again, providing your diffs ok.