Cool! Sounds like you found a good repair shop that was honest and reasonable. Plan on doing a water pump job next winter if you plan to keep the engine for all the reasons I mentioned.
OK, well the Merc oil looks fine. You would use approximately 1/2 pint of that oil mixed the 2.6 gallons of fuel. Please remember to use the fuel stabilizer as well.
I’m glad this engine is working out for you. I know I presented many “cons” to these engines, but I still like them. A little extra maintenance will keep it running for years.