My understanding is that Universal says that these are all they have, the other stuff was destroyed in a fire. It doesn’t exactly make sense (somehow the LHO got expanded for the UK), but I think it’s fair to say that “Trilogy” won’t ever exist in proper HD.
I have an mpeg ripped from a VHS of “Trilogy” with all of the extra footage, I would gladly contribute that to somebody’s project. I wanted to do it myself, but I hit some technical problems with the DVD import and I don’t know how to do a “proper” upscale to cut VHS in with the Bluray footage. I would LOVE for somebody to take this project on, I actually think most of the extra footage is good, and one shot in the episode somehow got flipped for the syndicated cut so there’s a non-broadcast goof in the HD version. All that I would want in exchange for this copy is a digital copy of the completed restored version.