HI all. I just acquired a 74 mercury 650. I noticed that it appears to be leaking some oil from the prop shaft seal. I have been looking for several hours online trying to find the right part number for the complete lower unit seal kit. I can find them listed for just about everything else. I do not know what other motors use the same lower unit so I could cross reference to something that will fit. Serial number is 3809752. I figure one of the local mercury experts might chime in and enlighten me. Thanks in advance