Have you tried sending an email to Aurycle? They seemed to be doing a lot of buisiness when people were first building their DIY-U87's. If/when you find out, let the forum know as Aurycle is a great source for cheap donor mics. Thanks.
I send an email von 1/25 and get an answer on the same day. I asked about the A460Kit and Aurycle answer me, that they will com back at the end of february.