I was just taking a second look at your threads. They are fantastic. If I may ask, what are you using to chase those threads with? Any tips you'd like to pass along? 8^)
I use a set of Crown 20TPI thread chasers, i started chasing about ten months ago.
Threads are all about patience and practise, there are a couple of tips, always turn the female thread first, then chase the male to fit, patience and practise will perfect the techniques. Also to ensure the female thread is parrallell i use a lollipop stick