An update seems in order. First, I decided to go ahead and split the case, just for my own piece of mind. Haven't dug into it yet, but should be a good winter project. Also, the engine log was located by my Grandmother-in-law (I inherited the motor from her husband), so I now have a lot better idea of the history. Going through the logs was a fun exercise on it's own, given the interesting past. Thanks for the advice! Now, are there any other resources out there that I might want to look for, besides the overhaul manual and IPC, before I dig in?

Patrick