How about Science Museum @ Wroughton
Science Museum have their "big equipment" storage facility at Wroughton just outside Swindon which could be an obvious location ... only issue would be access as its only open on selected weekend and their plans to redevelop into a major museum/education site didn't get Lottery funding.
Also, Bristol isn't far away and given "Silicon Gorge"'s claims to be one of the major centres of hi-tech in Europe you'd hope that it might be the sort of place that would want such a museum. However, we did have an excellent "Industrial Museum" until last year ... but the council has shut that down to redevelop it as a "Museum of Bristol" which sounds as if its going to be full of items on people recollecting that "we had trams when I was a child in Bristol" and other such touchy-feely rubbish ... also the fact that a display promoting the new developments outside the site last year had as one of the major aims of the museum as "having a large and dramatic entrance atrium and shop" gave a hint that its not going to be the same place that it used to be.