Piston chewed-up, will need replacing, think everything else is somehow OK!!

I was holding my breathe when I took the cylinder off, but - excepting the squish band in the combustion chamber - everything in the bottom end & cylinder looks A-OK!!
SO- Re diagnosis- this saw was a bear to start from the get-go, which I presume is when it initially ingested something via the huge muffler-exit, the saw then ran for nearly an hour on-job and failed. My carb-tinkering got it running, with me falsely presuming I "fixed it", but the hard-starts never returned (in fact, w/ Idle up 3/4ths a turn, I could start it with my left hand like my 590!) Presumably whatever had been stuck in the cylinder, had gotten out, and the extra carb-tune was to accommodate the huge exhaust-duration of a chipped piston! I did a few sessions (unknowing Re the piston, had even gone and put a new 25" B&C on it), was getting it tuned & ready for its 2nd job, when - shortly after filming a prior video on this channel - when it failed again, thankfully this time the piston was in right position when I inspected muffler for crap having been sucked-into the big exit-hole and I saw the piston's damage, was scary not knowing just how much of "my precious" here was damaged, thankfully it appears a buffing/refinish of the cylinder's squish band, and a new piston, are all that I'll need to have this guy back in-action (well, and a finished version of the muffler I'd intended to build from the start...woulda/coulda/shoulda but damn what a headache it would've saved!)
Still as in-love w/ this platform as the day that Fedex dropped those boxes, was already thinking "will just buy a blue thunder 'base' and move everything over, if I have to" lol!!! The modular, easily replaceable (and workable) nature of this high-output powersaw make it a platform I intend to use til I'm no longer sawing :) Only question is whether the next unit is m-tronic to save me from myself!!

[@joescissorhands141]

One consideration/fear of swapping ONLY the piston, and not piston + cylinder, is that because this saw was custom built, with a cylinder whose base was machined to spec., the only way for me to "fit" a new piston is by altering squish via base-gasket height (thankfully it came with a large gasket, so there's some room to play, all the way down to a thin smear of Motoseal!), BUT this would effectively change the port-timing of all ports, changing it from "woods port" to "random-port" in a way! I'm sure "it'd work", but if it's smarter to just get piston & cylinder that are "known matching pair" then maybe that's smartest, though to lose this pro-ported cylinder would be a shame!!!

[@joescissorhands141]

Update: to remedy the whole fitment-issue I may've gone a bit overboard....By mail-time on Tuesday at the latest, I'll have (4) cylinders, 3 good pistons (1 is a pop-up piston), 2 new sets Caber rings and NO none of the cylinders are titanikel so this will be a "game of porting" (one of those 4 cylinders comes attached to a built g660 powerhead w/ full-wrap bars, so will be doing a 2-platform 660 build here!)