Re:What's the difference (Score 1)

between the one in the Science Museum and this new machine? TFS states "two tons heavier", but the article doesn't mention it, nor the CHM website. The London machine weighs 5.5 tons including its printer, the CHM machine also is listed at 5 tons. What gives?

AFAIK, they're identical. I don't think S/N 1 at the Science Museum was ever precisely weighed, but S/N 2 had to be for the air freight shipment. There has also been some confusion over whether the weights were in US or long tons. The most complete sources (Doron's IEEE Annals article, derived from his book) says 5 metric tons, which is 5.5 US tons.
chmguy