Congrats Mike, that is a nice start.

Classic Arcades sells the complete drop target set for Paragon, and you can find them on eBay. Marco Specialties and other stores might sell them individually so you could possibly add it to a bigger parts order from them.

My guess is that some of the hardware may be missing so I suggest that you upload a picture or two when you can as it will allow for the group to make suggestions and guide you through repairs.

http://pbresource.com/pfdroptar.htm

Pinball Resource has everything you need.

While touching a rubber can keep a drop from dropping the "Bally Brick" is a well known phenomenon that causes the drops not to drop when you hit them. If you rule out any physical issues then you have to live with it

I’d you’re getting new drop targets, have the waterfall targets been changed too? Maybe they’re not the correct drop targets and that’s casing the bricking ? They should be “explosion” style . Photos ?

some times if you stretch the rubber and put most of it in the back it will thin out in the front , if not try a smaller dia rubber