How certain are you that they married in 1866?
and that it was in Somerset?
If I have the correct couple -Henry was called Henry george Wheadon , and on one census is known simply as George.
In 1871 they were living in Dorset.
There is a marriage freeBMD
Sept qtr 1865
Chard
Henry George Wheadon
Priscilla James
5c 737
I'll see if I can find priscilla james pre marriage -and see if her p.o.b. matches
Suz