Flush #7 and we're moving right along. I've run the engine a couple of hours with its current oil - I think I'll be ready to install the new cylinder and piston kit after draining.
Speaking of which - the cylinder arrived with slight damage to the upper-rear-left cooling fin. It's just cosmetic, so there are no complaints from me - except for the seller! This resulted in a $23 refund and in my mind, effectively resulted in the purchase of a functional blemished item. That is A-OK with me!
I was also able to find a cheap M35x1.5mm tap that I used to fully repair the crankcase's damaged threads for the oil drain plug. First I laid the bike on its side to keep the oil in it. Using some small pieces of foam cut from a floormat, I plugged the oil ports to prevent any shaving from getting into the crankcase.
Next, the side cover had to be removed to allow for clearance of the largest tap I have ever handled. Once the tap was lined up properly and beginning to chase the threads, I used some q-tips to clean any shavings that built up instead of letting them fall. All fixed up!