This unit is still old and it seems so that this particular one hasn't seen a cleaning in his whole lifetime. There is so much dirt, dust and other oddities that it takes a while to bring it's beauty back to the sun ... take a look at the photos before cleaning.

Photos after cleaning ... The Keybed needs a lot of cleaning and adjustement work too, because it was in a incredible bad state delivering only rare triggers and floating keyvoltages.  

A little modification was neccessary to fix a problem with the keyboard trigger pulse. But now it works fine again and is ready for the next 50 years ;o)