I thought the "sawing people in half" act was done on many kids shows. Though now I'm having trouble thinking of very many.
Of what hasn't been mentioned, it was done on Dinosaurs.
It was mentioned that it was done in the Looney Tunes short Show Biz Bugs, but it was also attempted in the short Merlin the Magic Mouse (though Merlin never actually completes the trick - he mistakenly uses a real sword instead of the magic sword, and after he learns his mistake, the cat "volunteer" finds out he's a mouse and chases after him). I feel like it was done in other WB shorts, but am unsure off-hand.
It was done on Bullwinkle in the Mr. Know-It-All segment "Magic Made Easy (The Hard Way)". Interestingly, this one has Bullwinkle sawing a man in half (he also says it's the least-requested trick - he probably meant the sawing in half part but I can't help but wonder if he was referring to the "sawing a man" part).
I'm trying to remember whether Pee Wee Herman did this trick during his magic show in the Pee Wee's Playhouse episode "Now You See Me, Now You Don't".
Also trying to remember if the trick was done in the special It's Magic Charlie Brown (wow, both of the above-mentioned things that I cant remember whether the trick was done are ones where the star turns invisible with the risk of not turning back to normal). I know it has a similar trick with Peppermint Patty in a box that's cut up into three halves, but that's not exactly the same as sawing a person in half.