That's a nasty looking piston. It will be interesting to see how the bore cleans up. I once had a Chevy 283 that I disassembled with the motor in place due to oil burning. I fitted new rings and reassembled. One bore was scored, probably worse than yours but I didn't want to spend the time and money to pull and repair. I probably got another 50-60k out of the motor before that cylinder started fouling plugs frequently.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13