RA, I have been to many rendevous here in uk - there is a place called 'the land' near southampton, where a old style fort and trading post is built and here people do all the things you mentioned.
I dressed as a mountian man - full buckskins and the raccoon cap in the picture with the knife. Made all my clothing ect myself so a useful learning curve there too.
To become a member you had to pass a survival test which was basically to camp out equipped with only 18th C tools. It was great, build a shelter, light a fire, set your snares and chill!
ack:
An excellent hobby but alas to far to travel regualrly.