unfortunatly i can tell you that you will NOT!!! find these membranes.
im 100% sure of it.
ive tried it for more than a year.
if you want to solve this problem using membranes You can use the 050TI, 052TI, and maybe , maybe the 035TI.
but there all silvercoloured domes. re-doming them would be a realy difficult job.
sorry mate suck it up and buy the new tweeters. 500 euro
for a nice (not mindblowingly good) tweeter.
id go for a 050TI for 120 euro's.(a pair, inc posting) exactly the same.
orange county speaker parts or something sells them and will send overseas. just google for a while
in my case they would fall out of place since my whole speaker is gold.