Lost Key Found! Will Meta Fob Work....

After three months, I found my lost spare key in the grass outside my office where I had obviously dropped it. I was cutting the grass when I spotted a glint of metal. There was my key with attached Meta fob, covered in dirt and, as I subsequently found, full of water! I opened the fob, tipped the dirty water out and proceeded to clean it up as best I could, drying it thoroughly afterwards with a fan heater. The circuit board was very furry, and I chucked the batteries obviously, so I have ordered new CR1220's and keeping my fingers crossed it will still work! I had actually bought a new key blank, been given a new transponder chip and spent 50 quid on a new Meta fob - but not got round to key cutting or programming, so might have a third spare if the recovered one works. Anybody any experience of bringing back a Meta from the dead?

Here it is after cleaning, the big chip at the top above the microswitch was very furry!