These are the knobs:
http://www.bobsknobs.com/Meade/Newt/MLB16.htm
Could be you could make or find some locally, but he ships worldwide for the posted price. If you just stripped the head of the collimation screw, you can probably back it out. Remove the secondary from the spider by unscrewing it (the center bolt). Careful, a spring will pop off the back as you do....I'd just set the un-attached UTA on a table or something, not do it with scope assembled. Then you'll be looking at the business end of the collimation screws. You can either just wrap the threads in a rubber mat and vice-grip turn them out, or find a locking nut to put on the end to give you some traction and reverse it out. Just don't damage the distant end threads, or it'll hang as those threads back out through the spider body..
Cheers
Scott