Yes - 6000' matters. Add 18% to the values for a sea level equivalent. The oil deposits on the plugs are likely a combination of valve stem seals and oil getting past the rings. I'd make sure your carburetor is working well and just drive it.
When doing a wet test, don't add a ton of oil, as it can affect the value by its volume. Your compression jump on cyl. 1 with the wet test seems high to me - that's more compression that I have ever measured on a 2F at this elevation. I use a pump oil can with ATF in it and use the same number of 'squirts' per cylinder to be sure I'm not careless with the oil. You might try another compression tester, too, in case yours is off one way or the other. I wonder how accurate mine is, for that matter.
A 2F won't be a rocket either way - it's a tractor motor. I'd just drive it and run at least 10w-40. Perhaps replace the valve stem seals to cut oil burning.
Colo Springs, CO