My best friends are a couple of which the man was very interested in religion over 20 years ago. I was always trying to tell him about the JW-religion and he even came with me to the KH. His wife (well, not actually married, but they're together for nearly fourty years) came along and didn't like it one bit. After the visit to that one meeting she refused to talk about it ever again. After a couple of years our contact was gone. The man wasn't really interested in becoming a JW and my ex-husband didn't like them very much to spend time with. So it ended.
But six months after I got DF'd I phoned them, out of the blue. Just to ask how they were and I told them what had happened (divorce, DF'd) and ever since we've been friends. And they are my only REAL friends, the ones I can count on always, even now I'm living in Spain.
Funny thing is that I totally forgot that your way of 'finding new friends' by contacting your old studies is exactly what gave me my dearest friends!