I doubt that you can find more tracks by her on cd or online...however, I am certain that if you were willing to spend a little bit of money/time, you could find a lot of her songs on vinyl. She was primarily an actress, so I am not sure how many songs there are out there. I think that So Little Time is online and on cd primarily because of Morrissey's under the influence.
I was going to say "listen to Marilyn Monroe until you find more Diana Dors stuff"...but we all know that the only thing they have in common is that they're blonde bombshells.