Just thought I'd update.

I left the test light on the battery for a week or so and then waited a few more days. I then hooked up the charger on a 2amp charge and left it.

When I went back to look (the next day as I forgot about it overnight) the charger light had turned green and there was a big mess all around the area where the battery was. The battery seems to have let some gases leave, but the fluid levels still looked good. I flicked off the charger, disconnected and tested the voltage. 12.4 Volts. Nice!

I then left it for a few days and went back to check and it was still in the 12 volt range. I hooked up the charger and let it run again on a 2 amp charge and it turned off after an hour or so. Checked the voltage and just shy of 13 Volts. I then left the battery alone for a couple weeks (we were packing up to move to a new house). When I finally got a chance, I decided to take the battery and hook it back up to the snowmobile. Turned the key and the machine started wonderfully!

Looks like I got lucky. We'll see how it holds out this winter.