Sorry - I misread your original post - I thought you meant the right bank. You mean the right target in this photo:
http://ipdb.org/showpic.pl?id=4442&picno=21441
Yes, the P/N above is correct. It's a modular standup target that was supposed to make it easier for ops to repair when a target broke. Unfortunately, while Stern sells either the entire assembly or just the target, they don't sell just the switch actuator/black plastic housing for the target because in their words, "History has shown that the actual switch housing unit (the black casing containing the Switch Actuator & Micro-PCB) has had little to no failures."
I've had the same issues you've had and had to buy the entire assembly.
Anyway, everything you ever wanted to know about the modular targets including part numbers:
https://web.archive.org/web/20121114170110/http://www.sternpinball.com/downloads/sb110.pdf
viperrwk