Took those vids w/ my iphone.
Thanks for the info spareparts!
I am going to try and take another set of dry/wet compression readings on cyl 4 tonight simply because I'm not convinced I did my first wet test properly. This time I'll use a tablespoon of oil and give it a little more time to flow down into the rings.
I'll take a look at the riser gasket as well. Sounds like it's a common issue. If that does turn out to be bad, could I just replace it for now and wait until the offseason to have the valves redone?
Thanks again.