That is exactly what I was told (Samut Prakan) and my first year extension was based on marriage, I then met the requirements for 'based on retirement' and switched to that for the following years, without any fuss.
When you say 'on marriage visa' I assume you are on a one year extension based on marriage?, if so why does your current 'extension of stay permitted to' expire?
Well for the last 5 years just a copy of my updated bank book has been accepted at IM and there were no missing transactions in that book as it is a time deposit account.
The UK too, but you cannot travel on the old Passport. In Thailand they allow you to keep the old passport because immigration requires that you have it to prove your immigration status. In this case it is immaterial as the visa is also expired.