Powersteering reservoir O-ring size?

Hey gang,

After looking over a few old posts, it looks as though my powersteering reservoir O-ring has gone on my 2.5L '98 OBW. Tranny fluid is leaking down the front of the engine. I'm located overseas and finding the correct O-ring could be a week long effort only to be told that it will have to be ordered. Does anyone know the correct "size" O-ring that needs to go on the bottom or is there anyone out there with easy access to the correct size O-ring that would be willing to drop it in the mail? I'm assuming it will fit in a standard envelope. You'd be helping out a Subaru lover who, against my better judgement, owns a Subie in a Subie unfriendly part of the world. I can send $ via paypal, check or cash through the mail to anyone willing to help a fellow Subie lover...

Thanks.