I notice from the actual burial register that Munson Mills was buried in Langham but his residence was quoted as Dedham. I also found the burial for a June Mills age 67 at Langham 21 October 1827. Baptisms for their children were found at Dedham. Let me know if you haven't found these, they are James, John, Thos and Sarah. I tried to find a marriage in Dedham or Langham for Munson Mills and June without success. Their son James appears to be in Brightlingsea census 1841 and 1851 at least and Thomas is in Gt Oakley in 1851.
There is a William Munson Mills bc 1825 living in Wivenhoe in 1861 and 1871, he has two different wives for these census but says he is born Nayland, Suffolk. I will send a direct message to you regarding this gent as I have a contact for this persons line. He was baptised on 10 Mar 1824 in Nayland, Suffolk to parents William John & Sarah Mills.