It wasn't uncommon. I've had it in my own family lines and it's hard if the present generation refuses to acknowledge there was a change along the line. There are a lot of conversions through marriage. As for the Quakers, if a Quaker married ( or marries, if it is still the case ) outside of the religion they were dismissed for marrying contrary to doctrine. So, if your Quaker married a Methodist, look for lines through the Methodist church after the marriage. I'm doing some research not connected to my families, and I have come across a dismissal in some of the records for my volunteer research family. I hope this helps you a little. All of the Friends Meeting Houses keep and kept meticulous records and you should find a great deal of information for the party before the marriage, plus you should also find when he was dismissed, as it will be noted in their records. Helen Dee