Just while we're thinking this sort of thing, people might be interested to see http://www.meccano.us/ http://www.meccano.us/. I believe Tim helped Andrew on hi

Just while we're thinking this sort of thing, people might be interested to see http://www.meccano.us/ http://www.meccano.us/. I believe Tim helped Andrew on his Lego difference engine, and he's now working on the Analytical Engine.