Driving at a restricted speed and limiting my throttle usage so as not to stress the newly-rebuilt engine didn't just take longer; it was actually quite tiring to keep it up for hour after hour, and I felt rather knackered by the time I arrived in Cambridge, about six hours after I set off at 06:45AM. On the plus side I appear to have set a new personal record for fuel efficiency: about 45 - 46 MPG. I had hoped it would be higher as I have already managed 44 in Fenchurch while driving at a less sedate pace.
The point of the trip, as well as running in Lintilla's engine, was to visit the Teslathon at the Technology Museum (which turned out to be the town's former sewage pumping station!). I had a very brief look around the place, then went to meet bugshaw, major_clanger, and aardvark179 in a local pub. I was the first to arrive and while I was waiting a friendly drunk at the bar treated me to a ten minute rant on the subject of economics and politics ("Margaret Thatcher would never have let this financial crisis happen.")
The Teslathon itself was... Slightly anticlimactic. There were fewer machines there than I had been hoping to see, and none of them were of the singing variety. Worth seeing if you're already in the area but I don't think I would travel so far to attend it again.
Afterwards I headed over to ms_cataclysm's place, who had kindly offered me her spare room for the night. I took the opportunity while I was there to drop off the_magician's two months' supply of food and water that he had left over after the AIR. Later on we went for dinner at a pub in the town centre with bugshaw major_clanger, and ms_cataclysm's fiancee, who had won four free meal vouchers by being supremely awesome at pub quizzes.
The drive back this morning was rather less tiring than the drive down, and it somehow took a whole hour less despite continuing to stick to 50MPH and stopping for lunch at a Little Chef. Lintilla has now done nearly 500 miles since the rebuild so I should soon be able to start driving her at a more normal (for me) speed! First though I have quite a few things to sort out before I can get her MOTed. It expires on the 6th of November (next Thursday). Before then I need to replace the headlights, headlight buckets, and headlight looms; do some welding on both sills; sort out the problem with the driver's door not shutting properly; fix the indicator switch warning light; replace the front seatbelts; and generally check her over for any other potential failure points. wibble_puppy and I have hatched a cunning plan to put both Lintilla and Emrys (her van) in to be tested next Wednesday. That way whatever happens we can celebrate and/or commiserate together! :)
 May be a slight exaggeration.