I have been rebuilding a variety of motors, including the J/E 6s for the past 15 years, not as a job as I have been retired for that long. The hands are starting to hurt now but I still manage. Just finishing a 1986 V4 john right now. My shop is basic but well equipped. No, I'm not suggesting that I do your motor but I can help you do yours. You will need a hoist and an engine mount. I am in NC and have my boring done by Pro Outboard in Lake Wylie Sc. First class shop which can supply the WSM pistons, gasket sets and carb rebuild kits, plus anything else you might need by way of parts. If you are going to the trouble of tearing down the motor you may just have all the bores done. Depends on your budget. The bores may not show a lot of wear or scoring but they will probably be out of round. A light hone may do the trick but don't try to do it yourself.You will make a mess of it. This is a two stroke with cut outs in the cylinder walls. Nuff said.
You probably wont need a bore gauge or micrometer from what you have said. Ok, if you are going to do it the guys on this forum will be right there with you.