It will go for peanuts on E-Bay.

I would forget about the battery. Just get a hand held light meter, or learn to guess exposure, and you will get far better exposures than the in-camera meter would give you anyhow (and it will be far less of a PITA than stop-down metering anyhow).

If the battery corrodes (which it probably already has, or will) and ruins the camera (which it probably will not), just throw it away and get another one for $25. Sad that it is at this point, but it is.

If you must, just take the camera to a repair person and let them get the meter running for you.

Whatever you do, I would grab the camera. They are great.