Help fixing a vintage LCD Rotary watch

A friend asked me to look at his old Rotary LCD watch. He wore it in his youth but it’s not worked for a long time. I was hoping it might be a case of clean the contacts and replace the battery (maybe a reset procedure).

Unfortunately the battery was left in place and has leaked and corroded through the +ve terminal, which is detached.

I cleaned it up with some isopropyl but the detached terminal is wafer thin and I don’t fancy trying to solder it back on. I would say that the corrosion is confined to the battery compartment but I can’t be sure about that. The battery is a Renata 309.

I’m looking for a recommendation for someone to repair it. I’m hoping for my friend’s sake that the terminal can be replaced in some way. I guess a donor movement might be an option but there were so many similar models so that might be tricky to find. He’s happy to pay a reasonable amount given the sentimental value to him.

Any suggestions/recommendations for repairers?