1. Original part # is 43249D. If you GOOGLE "IH 43249D", you"ll find there"s all sorts of NOS ones out there.
2. The new part number is 374704R1, and it APPEARS to be available, but just over a hundred bucks.
3. If the plate is worn a lot, how much is worn off of the front face of the cam or the back of the timing gear?