You might try seeing if SOR has a replacement gasket for that. Or you could try scraping it off and use a generic carburetor gasket material cut to the right shape and see if it works. Generally you're not supposed to mess with that insulator plate, but in your case it's too late. There's lots of engines being parted out which you could grab a replacement off of too, if needed.
Rising Sun Bio
2F "Brahma" + Lockright, tach, Warn 8274, FJ60 Power Steering,
no more Sanden OBA
1FZ-FE factory lockers +
Safari intercooled turbo, CDL switch, cup holder, Metric TLC leather, heated seats, JDM switches, PUMA OBA.
Warn M12000 waiting for a bumper.
Limited TRD 2UZ-FE SOLD