Hello everyone. I have been working on converting my '77 varsity to fixed gear. I know it's not cost effective, but I'm doing it for fun and experience. I want to eventually try and go for all black parts, but some of them are posing hard to find. Sheldon brown told me I need a 21.15mm stem, is this correct? If so, where can I find a stem in that size with a 25.4mm clamp diameter in black?

Any help appreciated. Thanks!