valve help needed

i have a valve for my stealth but the stem broke and i have lost the tophat and the spring, if anyone has these spares lying about and wants to sell them that would be super, but if someone has the same valve model and could take measurements for me so i can get one machine that would also be great!

photos; http://s195.photobucket.com/albums/z183/jonnyhal/blodnob%20valve/

thanks in advance for any help, jonnyhal