My rear diff is going out and am looking for a replacement. 2006 Forester 4eat rear diff - it is a 4.11, not the same as manual (4.44) Hit me up of you have one.
I believe the rear diff in our 2004 H6 Outback is 4.11; not sure how to confirm that but it's available.
Here's the listing, if it helps at all -- https://mnsubaru.com/threads/2004-outback-35th-anniversary-edition-part-out.53064/
Good news. I found one online on one of the FB forums. It's from an 06 XT Premium which also has the limited slip 4.11. I did contact the Craigslist guy you posted above. He's cool as ****. He's been doing diffs for like 40 years and drivers a crazy straight track car, we talked for like a half hour as he educated me on all diff options and what they mean. He said that he is selling was on the shop floor to show customers how a diff works. His was 'open' and not limited slip like I wanted so I didn't get it.