Thanks to the mudclub community (Rich, Paul and Dave amongst others) I've extracted the engine and transmission from the chassis, so almost at rock bottom now! Just the axles and springs to take off (prediction: much grinding required) and then the chassis can go to the big scrapyard in the sky. One thing though- each wheel has a funny looking special wheelnut- like a round top hat disc and flange, with 4 holes in the flange. Presumably some kind of special tool is needed to undo it properly but what the heck is it?