Hi there. You are not the only one who is confused. I am as well. I got the dates for their marriage from the LDS Ancestral Record, which is not always known for its accuracy.
I am very interested in any Gledhill or Chapman photos you may have. If you can send me your email address I will send what I have (not a lot I'm afraid). I would also be very interested in taking a look at your Chapman data.
My email address is "email@example.com". We have probably been in touch before, but it is always nice to catch up again.