I don't think many. My other question is what happened to him? I thought when he didn't go back he was going to join the Avengers or maybe the Secret Avengers. Who better than Steve Rogers to help a time displaced hero? Also, I believe he has enhanced strength levels, almost able to lift 1 ton.
But getting to the primary question, I think the Avengers he met were those on current roster. Spiderman, Hawkeye, Spiderwoman, Thor, Maria Hill (was she or wasn't she an Avenger) and I believe it was mentioned that they handed him over to Steve Rogers. Quite possibly Ironman, Captain America and Wolverine. And since during this time Agent 13 was Steve's right hand person and if she is considered an Avenger. So that gives us about 10. Not very many considering there are over 100 members, not including honorary.


Mr Bojo