Hi, I guess I better introduce myself
Yes - I do make a few Sinclair related items. Started out with the Microdrive emulator (vDrive ZX/QL - didn't realise there was another VDRIVE associated with the ZX81 so hope I didn't offend anyone with the name). Went on to re-engineer the Sinclair Interface 1 ULA (the vLA1) and as I'd gotten the CPLD/FPGA design bug thought I'd work through the rest of the Sinclair ULA family. Ended up with a design for the ZX81, Spectrum 48K and Spectrum 128K and decided to bite the bullet and make them into something worth buying (hopefully).
I live in rural New Zealand and make everything by hand (along with small reflow oven to speed some things up). I inadvertently set my location to Germany while setting up a listing on SellMyRetro hence the rumour that I come from there (would certainly make it easier for shipping!). I've since corrected this but a purchaser from Germany (Paul?) happened to buy a vLA81 at the right time and scored very low shipping costs

. My mistake so if you're reading this Paul, then you've got a bargain!
Although I've tested the vLA81 as best I can and have had a few independent testers who have reported good things, I would welcome any feedback from forum members and also be more than happy to answer any questions on the features or design.
Cheers,
Charlie