Yes, while you're at it, why not add a generator, MIG-welder and angle-grinder to the list, just in case you should need to partially rebuild the thing at the side of the road!
Well, thanks you all for your replies - I think that the idea of a trailer is probably a good one, judging by the ever growing list of things to take!!
Things have changed slightly - we'll be going to our house in the Lot region of France (about 550 miles drive from Calais) where we'll be based for 3 months. We'll also be taking a motorhome with us, so it will be a drive through France in convoy. I've looked into towing A-frames: the law is unclear Europe wide, so don't want to take the risk - plus it would appear that fitting may be a problem as well, as the Morris doesn't have "homoligated front crash bars" to fit the A-frame brackets to I've also looked into a car transporter trailer: seems very expensive, and wouldn't get used often enough to justify the outlay, unfortunately.
I think the best plan is to go in convoy, with a decent set of tools / spares in the motorhome, plus this would mean that overnight stopping wouldn't be too much of an issue.
Apart from bulbs, points and a known condensor (all of which you can sling in the glove box) your mobile phone and the number of a good, knowledgeable friend is all you really need. Leave the trailer, welding gear, rollover cage, spare car etc at home. But don't forget the factor 50,