Very detailed documentation, thanks for posting a very specific and well researched problem.
Unfortunetly I think you may be out of luck on this one. I also reviewed the Service Manual for teh 1415 and it appears that the part that you need is not individually labeled for replacement. You would have to find the larger component that houses it and swap that entire piece instead. That larger piece is identified on the image you attached however it is not labeled with a part number to reference for replacement either. I couldnt find any other diagrams in the manual that would give me any more confidence for replacement either.
HP is not going to be of any assistance for this since your printer is out of warranty. It's doubtful you could speak to someone from HP Support that could assist you on someting this specific to begin with. Your best bet would be to aquire a bad 1415 and salvage the part for yourself since you are saavy enough to expose and repair it on your own. Otherwise it might be time to consider swapping the unit and going with something else.