I finally managed to very successfully mike up one of my sons cymbals.
I used piezo film contact mike from these guys in vancouver, BC
http://stores.shop.ebay.com/Cold-Gold-Contact-Microphones__W0QQ_armrsZ1
They cost Cdn$3 each when bought in bulk.
I first cleaned the lower cymbal surface with fine wire wool and cleaned with 99% Isopropol Alcohol.
I used micro coax to attach to the 2 piezo terminals ensuring that I isolated the center positive lead and piezo contact by taping it up.
I then used contact adhesive on the piezo film surface and let it dry, this will create a non permanent fix to the cymbal.
It is very important to have a good solid contact with the resonant surface and I will use cyanoacrylate at a later date, DO NOT use double sided foam tape as this acts as a damper.
I then used copper shielding tape with a conductive adhesive to protect, cover and electrically bond the piezo microphone to the cymbal surface, it is important that this shield has contact with the outer grounding sheath and not the centre cable core.
This ensures that any outside interference gets grounded.
It is also a good idea to isolate the centre core inside the mono jack at the other end and then wrap copper shielding tape around the ground before screwing on the plastic outer body.
This was tested through a 6 channel mixer/preamp and then recorded on the computer, excellent sound reproduction.
Next I am going to attach the piezo films to the inside upper wall of his drums.
I do not think it necessary or indeed a good idea to attach to the drum head as it is the drum body that has the resonance not the head.
Will let you know.