Why is the transmission process less fallible when you learn the song from a Steeleye Span recording? You are learning from Steeleye's arrangement, which is likely to contain many musical ideas of their own that were not in the version that they learnt it from.

Note that I don't call the latter 'the original version' because there is no such thing unless you can track a song back to the person who wrote it. But there is much to be learned from investigating other versions of a song and tracing it back as far as possible, as there is also from listening to the few available recordings of 'source' singers. When you do that and then go back to Steeleye's version (or Carthy or whoever) you then hear what they have done to the song. Whether you choose to emulate the later performers' idiosyncracies is up to you, but at least you have an informed choice and it may give you the perspective for an imaginative and completely new idea of your own. Surely that's better than slavishly copying one band's very stylised interpretation?

Anahata