Are you still looking for a TiBolt?
Here a frame in Germany in your size 18.5“
https://www.kleinanzeigen.de/s-anzeige/rocky-mountain-ti-bolt-18-5-47cm-retro-90er-titan-rahmen/2805058784-217-8080
Here is a cheaper one:
Thema 'Gabeln: Vigmos Titan 1 1/8" Ahead 395mm EBH' https://www.mtb-news.de/forum/t/gabeln-vigmos-titan-1-1-8-ahead-395mm-ebh.978279/