As he seems a bit old at 38 for this to have been a first marriage, I wonder if there is an earlier one. Have you checked the 1814 marriage entry to see if there is any further detail eg widower; of the parish of xxx; and the names of the witnesses?
There's a marriage in 1805 in Flamstead, which is half way between Sheep Lane and St Albans, of a James Anscomb which might be worth checking out. I can't see a suitable baptism for this James either. (I've just noticed on the BVRI that an Adse Handscomb dau of James and Charlotte was baptised in Flamstead on 23 June 1816. The 1805 marriage would definitely be worth checking - but I can't see any other baptisms in Flamstead from the 1805 marriage)
Where did you see the Langford baptism which fits, as I can't find it?
According to the Hugh Wallis site Heath and Reach extracts on the IGI only start at 1813
Regards
David