I can give some pointers that there are remastered Season 1-3 episodes floating out there, but a good lot have logos (but some are clean). Remastered, but with many errors/alternative scenes, one that comes to mind is in "Coal" where Henry backs into the siding at Wellsworth and just goes forward again from a blooper real, instead of the final master with Edward moving out as the sound effects sure as hell imply.

I myself have been converting the unreleased Thomas tapes for DVD. These being mainly the third, fourth and fifth VHS Volumes all with Ringo's re-narrations - "Tenders & Turntables & Other Stories", "Thomas Breaks the Rules & Other Stories" and "Better Late than Never & Other Stories". I've also done the compilation "Thomas' Christmas Party" tape with narrations by George Carlin. I've only "Thomas Meets the Queen" left to do. A bit off topic on what you're doing.

I look forward to the final results on your project. What the US gets is a sham, but we screwed Thomas up all together, so do we deserve much else? Of the original series, yeah....

EDIT: I noticed that you touched base on the remastered editions before. I foolishly posted before looking, so nevermind about me... :P