My father had the job of rebuilding and improving this machine when it went to Wolverhampton. He added an extra block of Decatron tubes to facilitate this but not visible on your photo. I remember 'playing' with it as a very young lad when Dad would 'pop in to work' on Saturday mornings. During the late seventies, around the time it went to Birmingham Science Museum, he put an entry of it in The Guiness Book of Records, 1977 edition I think, as the worlds most durable computer. I have a framed copy of the photo taken for this purpose, along with an etched nameplate which was on the control panel, and also the 'starter' key. In the early 50s' he appeared along side Witch on the front cover of The Times Educational Supplement in the days when it was a seperate purchase, demonstrating it to a group of school girls.