Jan contacted me and and provided additional information on George Avery, photographer, of Hitchin including a link to a useful family tree. George took over the business of Samuel Debenham in 1863 and sold the business to Thomas Latchmore in 1870.
At the same time as updating the family information on the George Avery page I have added two early photographs from about 1863/4. One, which has the hand written Hitchin address on, is of the Rev John Henry Howlett (1779-1867) who died in Kent, and the back suggests that it may have been taken in Kent at the time George was moving to Hitchin in 1863.
I would be very interested to learn of other photographs taken by Samuel Debenham (in Hitchin, Bedford or Luton) or by George Avery (in Hitchin or Kent).
[I have not investigated the history of the Rev Howlett - comments will be welcome.]