Hey Dave. Congrats again on the game! The part number for the drop targets is indeed DTP-001, and it’s correct in the manual. What you saw is the part number for the plastic above the CASTLE drops. The parts are broken up on different pages. What you were looking at was the page for ball guides, plastics and rubbers. Flip back to game specific parts, and in the exploded view of the drop target assembly you’ll see the number. For what it’s worth, Alvin G & Co. tried to make part numbers make sense somewhat, so if you see a number like BUT-M08, you know it’s for a plastic....or Butyrate. Anyway, what Marco has should be NOS, but I can sell you some as well.
As far as the blue translucent targets go, I’m low on the blue ones, but you can try to find round translucent ones and cut the sides off to make them rectangular. I did that a lot when I was completely out of the proper part.
I have an art file for the bullseye drop target decals here, so I can send it to you to print some new ones.