Got a chance to buy one and was wondering how rare they are and whats the going price?
They are called E2E Defender...
I just came across this yesterday. New Graham
not rare but are rather uncommon
That's the exact situation. They are the building blocks for black L4 and TW4 lights.
TW4 is basically a 1cell L4. An E1E body and a KL4. I'm not 100% sure on this but I think you need to use a 3.7V cell for it as well.
Yes to the first part - on the second, my KL4 runs on one 123 primary, but I don't know if they all will.
Mine will run on a 123 primary but does not give you a 100% output.