I have recently purchased a De Vere 203 enlarger and I am trying to source a 6x4.5 negative carrier for it....no joy on eBay and I just wondered if anyone here knew where I might get one from. I tried KHB but no joy
I had the exact same issue, I obtained some thin aluminium plate and got it laser cut. Just make sure you get the orientation correct, needs to be in portrait mode. Don't ask how I know.
Chamfer the edges with a file, take your time and get it seated correctly in the holder.