Dave,
It is your perogative to have a slot club member only meeting / trade session at a location paid for by the slot card club under any conditions you specify. I wish you well.
It is a shame though that the slot card club like the former slot card chapter is not interested in promoting membership in their own club by inviting people that are not current members to their meeting. Inviting non-members to your meeting would give them the opportunity to learn about your club. That in turn may encourage people to join. The current senario does not give people the opportunity see your club in action. It's your club do as you want at a location of your choice.
BTW, this policy was one of the two main reasons for me not joining the slot card chapter.
Paul