Having a darkroom sort out the other day, and found the split prism focus screen that I bought last year, put in the cupboard, and forgot about.

It was an easy job removing the standard chunky, curved screen and replace it with the new thin, flat screen but the retaining wire is the wrong shape and the front clip isn't long enough to put pressure on the wire.

I don't remember where I bought the screen. Is there somewhere that sells a suitable retaining wire and longer clips?