Sandberg are very much still in business. They don't make "stock" instruments as such because they are pretty small outfit, they basically build to order, some of which are custom orders and some are orders from shops for stock. In other words they don't just keep producing and stockpiling instruments, partly because they haven't got the capacity to, but mainly because they have so many options that it wouldn't be practical to try to hold stocks of everything.
If I were you, I would start by contacting Alan at Synergy Distribution (UK distributor), who is very helpful and will point you in the right direction if you explain what you want to achieve.
I think that PMT and GuitarGuitar are the only stockists now, although I believe only the Epson GG store has any stock: when I enquired about a custom order with GG Birmingham recently, none of the staff knew that they could get hold of Sandbergs until I told them! The PMT online stock list is nonsense (they told me this!), but the Birmingham store usually have a handful in. When I was in there about a month back, they had a few Basics, an Umbo and a California VM, and I think that was about it.
Have you seen the California TT on eBay at the moment?
Hope some of this helps!