I wish I lived in Florida. Even if only for Jon-Marc's sake, I would do whatever I could to find or establish a Biblically-based, naturist-friendly church, particularly in Pasco County. There is a HUGE mission field that can be harvested right there.
Many naturists are like Jon-Marc, disinfranchised Christians, pining for fellowship. Many are already spiritually minded, but have not discovered what a relationship with Christ can bring into their lives.
I am not sure that I agree with the statement that the "retired" demographic are a part of Jon-Marc's problem. Many of the people that I know who have reached retirement age, even those that are very "concervative", have experienced enough nudity from hospital visits or caring for elderly parents, that they are more understanding and accepting of simple nudity. If anything, it is the younger generation that seems to have the greater hangups when it comes to the naked human body. That might explain it better, since many of the churches I have been involved with or witnessed seem to be working very hard to attract a younger crowd. In fact, one church we felt compelled to leave had changed it's focus so much that they were seemingly purposely driving away the elderly in the congregation, the very ones who had established the church thirty years prior.
Also, part of Jon-Marc's problem is that he is limiting himself to KJV Independent Baptist churches, of which there are few, if any, in his area. The other problem is that he will not attend a church that will not allow him to sing as a part of the service. What he needs to remember is that his gifts are not for the congregation, but for the Lord. God will hear his sweet voice just as well in the pew, at the front door or out in the parking lot as He would from the pulpit or choir loft. Also, he needs to give the pastor and the church members enough time to get to know him as the God-loving person that he is. He may have to sit and listen to 100 sermons on the evils of nudity. Then, perhaps not right away, he can show them that he is worth to be a part of the praise team and they will accept him with open arms.