I've compiled a quick sheet just to start this thread. It is very WIP right now so I encourage you to post you IJN parts here. Common systems (i.e. not unique) that were used on multiple ship classes preferred.
Please pay attention to the IJN nomenclature as I found it to be very tricky and often quite inconsistent. Also I might be able to provide plans for some parts if needed as I've collected a lot of them.
I'll try to do my best updating and managing the sheet but it might be pretty slow due to my lack of spare time.
Please don't bother drawing IJN boats; I got this