Hello!
For a long time I see only questions about where to find Sam keyboard membranes, but I do not seen anything what may help in producing new ones. Why not take check now much membranes needed and not ask for help some small company which does such kind of layers for other devices (security systems, cell phones, handhelp computers, etc) ? I am sure if there will be something like hundred of membranes, such company may help us. In other case there are a lot of such companies in any country. You can also add order for different models of Speccy membranes (48k, 128k, +2 and +3 ones). Just post a request to c.s.s. and I am sure you'll have a lot of orders! For example I know a man who does not only absolutely new membranes but whole keyboards for local Spectrum clones. It includes membrane, plastic keys, spirals, and even external keyboard's case! Of course price may be a little bit more than we all want, but real Sam keyboard worth it, isn't it ? So, if someone have camera, scanner, working or non working Sam membrane and some spare time, please, make pictures of keyboard and membrane, split membrane into layers, take ruller and check all sizes between tracks, then, write something like diagram with all these sizes (in Mm and Cm). And upload that diagram and photos to the Net (on Nvg or on your own site). May be someone will find a company and then we'll have new working membranes. I can ask that man who does Speccy keyboards for help. I am sure membrannes will be cheap (~4UKP each), but shipping of such small and light weighted thing may cost 5 or even 10 UKP, because sort of protection required (seems like international post does not cares about final parcel's state, they only have to deliver).