I like the teflon type(perfect circle) ---if you replace the guides, you will just need the size to fit the guide od---generally .502 guide---on heads that haven't had guide work, they are cut to .531 with a piloted cutter--simple operation-- for higher performance engines I prefer the bronze guides---can even be a liner fitted to the stock guide boss--these then have a spiral tool ran thru then=m which sweges the liner out and then it gets reamed/honed to size---the spiral then holds some oil in the grooves which help lubercate the stems

From what I've seen in your deal---the loose guides/umbrella seals with one bad piston/cylinder(excessive blow by) overwelmed the PVC/breather system and actually forced oil from the high pressure crankcase via the easiest route thru the 2 intake guides

A note for everyone about compression tests----they will always be hifh with oil in the cylinders sealing the rings---a better test is the cylinder leak down test---this one cylinder would of been 40 % or more