I too own one of the 100 Sigma anniversaries bought for my 21st Birthday in Denmark Street London, 1983. Great tone, crisp and with the Fishmann pick placed inside plays well through an aer amp.
You can see me play on You Tube in Santiago de Compostela Cathedral Spain. Check out one being played. Would love to hear any other Sigmas live? Anyone got a link? http://www.youtube.com/watch?v=BMckvgUcAYY
Been playing it for years at gigs and it still produces a full bodied sound. Will never part with it as it has too much sentimental value.
Fr. Anthony ofm