Interfacing to LaCrosse WS-23xx Weather Station

Looking for some help in getting the Uno to talk to the WS-2310 I have. It has a 9 pin RS-232 interface. Just about every 232 shield I can find for my Uno says they are TTL levels. I got this station some years ago and I doubt its only 5v TTL, probably 12v true RS-232.

I would like to log station readings at various intervals to a SD card. Periodically I would then have it send the readings to a website and clear the SD. Have the ethernet/SD shield and have been working on learning the ethernet library. Have to pick up a uSD on the way home today to begin learning the storage library.

Does anyone have links to RS-232 shields that will take the old school 12v signals? Also, has anyone done this weather station interface before that has some sketches they are willing to share?