disassemble - inspect - repair - reassemble
Good work, You're half way home. It could have been much worse. At least you didn't snap a connecting rod and put it through the crankcase. As much as the damage is really just bore/piston related, I would tear the whole thing apart and clean everything well before reassembling. If any pieces of metal are in the main bearings, crankshaft, oil pump, or big end shells, then your quick rebuild will be failing and coming back apart in short order... For all you know the big end shells are scored too judging from the looks of the piston... You can do it. Take your time. In the spring, it will be back together pulling like a freight train doing 100mph up hill. You'll be confident that it's all new and solid as a rock for years to come.
... and the bad news is those circlips are not soft metal like aluminum, so you could be replacing a lot of stuff, like the cam, the oil pump, lifters, and anything else that suspended metal particles in the oil can destroy. You'll be inspecting a lot of stuff and making a lot of judgement calls on what is good and what is "toast". That can be expensive and stressful. Patience is manditory, and asking this group questions when you're in doubt is a blessing. I might call Jim comstock and ask if he would inspect and repair your barrels. I'd send him the head too. Then you know you're getting the best advice and the proper machine work to go forward.