Herps in Dorset

The trouble I seem to face in Dorset is that I seem to be able to find decent numbers of reptiles, but only as long as they are the same species that I can find back home in Yorkshire, i.e. Adders, Grass Snakes, Slow Worms & Viviparous Lizards, and I never have any luck with the extremely desirable Smooth Snake or Sand Lizard. In part, I put this down to having no experience with those species, never having seen one, and partly down to not knowing the key areas, as I don't live anywhere near the area. 

In truth, however, I assume it is more to do with me not being particularly good at finding things.

The notable exception to this rule is Wall Lizard, which I have seen in copious numbers at Boscombe, but then I have been spurned by its introduced room-mate, the Green Lizard, at every attempt.

I am not going to insult anyone on here by asking for specific sites and places to look for these reptiles, as I understand the necessity in keeping these sites out of the public domain. 

I will, however, ask if anyone on the forum is planning on doing any survey work or recreational herping in the second week in April, and wouldn't mind a couple of herp-starved enthusiasts from the North tagging along, then please let me know. I would be eternally grateful. I could even compose a dreadful song in your honour.

On a slightly related note, I wondered if there were any populations of introduced amphibians that could possibly be seen in Dorset. Up here in Yorkshire we get Alpine Newt & Marsh Frog, but not much else. Any sites for Pool Frog, Edible Frog, feral terrapins, Midwife Toad, etc., etc., would be gratefully appreciated, but once again, I can understand the necessity in keeping certain sites quiet.

Thank you for reading.