So, I reattached the carb, did "the right stuff" trick with the valve cover gasket and reassembled almost everything. I finger tightened the valve cover bolts with the socket and then did about one extra turn with the ratchet. It seemed snug but I didn't kill it. I also put a quart and a half of 10-W30 in it after draining it out to pull the valve cover yesterday. I'll fire it up after work tomorrow, too late tonight to do anything. I had to detach the muffler entirely to get everything to go back together... I *hope* the gasket doesn't leak, but if it does then I have a replacement in the mail already anyway.
I'll get a video of it running tomorrow, assuming it starts up and runs. It's on the battery charger for now, want to make sure it's ready to go. If the blade deck still works then I've got myself a nicely fixed up riding mower. Fingers crossed...