Marco has some of the drop target parts. I could only find the parts through the part numbers out of the manual though.
I got my cheese trap brackets from pbr about 6 months ago. If you need I May be able to find there part#. You May need to call them to see if the have any. Make sure you have a part # out of the manual when you call.
As far as ramps, I'm been looking with no luck. I've seen a couple come up for sale here on pinside but I can never get a reply.
Good luck