Oil Leak Confirmation ??

I have a small oil leak, appears to drip from my shifter lever enough to leave about a quarter size mark on my driveway every night



I plan on replacing my chain and sprockets this weekend, I know that I'll be replacing the gaskets on the side cover but I was hoping someone could tell me what gasket I need for the shifter, figured while in there I could replace that as well.



Thanks in advance !