With the damage that close to the transformer itself, I'd be concerned that the windings may have also been cooked and damaged. I don't think I would really trust that transformer.

Personally, I would start putting feelers out for a replacement transformer.

There is this one on ebay, but shipping across the ocean might be a tad expensive: ebay.com link: Williams 15B6797 Transformer

An untested one, but it looks like it was in a flooded game, so it may be questionable: ebay.com link: Williams Pinball System 3 7 Transformer Assembly AS IS untested

This one may be promising: ebay.com link: Williams FLASH PINBALL Power Block Transformer 15B B797 Mepco 30000 uf Capacitor

You gotta snap up those hard-to-find items quickly before someone else nabs them.