From one Hoover TT owner to another, I "feel your pain".
Sadly Hoover TT's went out of production in the United States 30 or some odd years ago and many of the small applinace repair shops either discarded what they had and or sold out of stock. Up until recently a few places I'm told did have the odd part, but whenever I contacted them the answer was the same, sold out.
Unless a member can furnish you with the parts you require, the best solution would be to order them from Great Britian, where Hoover only recently stopped producing twin tubs. Several online dealers have spares for Hoover TT's and most parts like belts will fit United States models. Have posted a link to one site below, but you can search on "Google" for others. You will have to find the British counter part to your model, but believe most belts are "yellow" or "red" dot for spinner and pump belts.
You may also try the Yahoo group "Twin Tub Empourium" or "Hoovermatic", (may be off on spelling/exact names), for more assistance. These are forums made of mostly those in the UK whom love/use twin tub washers. Posting is not as lively as this forum, so it may take several days before a response to your query is posted. You can however search postings for ideas and solutions to your problem.
Finally, was once told certian Hoover vaccumm cleaner belts would work on the Hoover TT. Have never tried it and am not sure so cannot give an exact answer. You could always find a Hoover dealer that has a decent collection of new and old Hoover vaccum belts and take yours over to see if a match can be made. Oh yes, check eBay, as various UK vendors/persons auction off Hoover parts. If you are going to order parts from across the pond, better off ordering a good stock to lay in supply while you are at it. Since Hoover UK stopped producing Hoover TT's parts will slowly die out as they have in the United States. Original Hoover pumps are already rare if not nonexistant.
Best of luck,
Launderess
http://www.diyitnow.co.uk/