^ I’ve bought from this guy on Yahoo a year and some change back. He made me some custom stuff for a project I’m working on (HAS powered SVG-8 all in one supergun) as well as a mahjong harness for a Sigma supergun. I have his personal email, so let me know if he doesn’t have what you need. I can reach out to him for you. He’ll probably have you buy something else he has listed, then will make what you need.
I’ve never used proxies, so I don’t know how the comms system work with them. When I dealt with him he had me input a message after checkout to remind him of the directions for that order. For example, he had me buy a different mahjong harness and then I added シグマ電子の用 (for use with Sigma Electronics) in Yahoo’s own message system for that specific transaction (only way you can message sellers directly besides writing a question publicly on the listing).
In any case, if you need help feel free to send me a private message.
Edit: spelling