i think i've screwed this up and put too much tape on and can't for the life of me, turn it the other way round so that the tape isn't exposed so much. Anyway ideas?
The fact that you can see the tape has no bearing on the success of the job. If it doesn't leak consider the job well done. If the exposed tape gives you worry that someone will see the tape and say it is a bad job, tell them that is how much you had to use to get a tight seal. If you really want to remove the excess tape, take a wire brush and carefully use it to remove the excess tape.
Expand the stuck female part with heat.
You could try heating up the part without the handle (female part). Start with boiling water (I worry flame will oxidize and discolor that fancy brass). Just that female part, not the whole thing because you don't want the male part to expand. When heated the metal will expand and grip less tightly.
Alternatively you could try the same thing with cold on the male part - shrink it down. I had luck with dry ice for something like that once.
easy work to undo if you own a vice, monkey wrench, or even a good set of workshop clamps... simply clamp the end and let the levarage work for you.
if you have a vice, use some wood to protect the brass from damage.
That tape has a great way of gripping the seal, but once broken, it will be easy to undo.