Darn, I've been three times to Cambridge and never even knew this museum existed.
Sounds like a cool event !
We've had a somewhat similar "repair day" idea here but it hasn't happend.....yet
Travel to Cambridge is a piece of cake, fly in to Stansted and there's a direct train line, takes about an hour IIRC. Its also a very nice university city, a great alternative to visit if you have seen London "enough"