I have the bulletin here (it's also in the files of the "The Lords of the Mini" group). If it's not available elsewhere I'll upload it. Another possibility could be this: http://virtual-music.at/webseiten_d/zubehoer/moog_d.htm (for some reason this isn't to be found on the English version of the site).
Message
[vintagesynthrepair] Re: minimoog pitch center detent
2011-02-23 by Malte Rogacki