Has anyone got a picture of a St.John's keelback snake (Xenochrophis sanctijohannis) please?

Answer 1

It's mentioned in Wikipedia & there is a photo of a snake head - unfortunately it is not very big:
http://en.wikipedia.org/wiki/Xenochrophis_sanctijohannis

There seem to be some for sale at Kearsley Tropicals in Lancashire (add on pets-classfieds.co.uk) - maybe the store owner would be willing to email you a photo.