I think I found the problem, I don't know how, but when I checked my haks, I found I was missing the latest tlk, one of the main RL haks, and the most up to date CEP Top hak. After downloading them, I logged in, and suddenly Shelgarn's Persistent Blade is showing up normally! I was also having a minor issue of a few other models being invisible from time to time, but Shelgarn's was really the main problem. I do not know how I have been managing to play, because I was subscribed on my Steam client and I have been able to log in for weeks, but I was certainly missing two haks and the up to date tlk file.