The best way to figure out the proper framerate is to compare to the soundtrack/score, if it exists officially anywhere. You would check the pitch and length against the video audio. One might be the same pitch, but longer or shorter
I don’t think the soundtrack was ever officially released on CD or digital for the TV specials. Only “The Curse of the Were-Rabbit” had an official release.
All I can find on YouTube are Blu Ray rips.
There is this, which is apparently a rare promo CD but I can’t find any more info anywhere else;
https://www.youtube.com/watch?v=VimZfYsDHkc&list=PLCE33B3B271AF3544