Turns out this was not the manual i was looking for. The concertmate 670 keyboard i have is a "Realistic" model made for Radio Shack and none of the diagrams on the owners manual i received matches up. HOWEVER, I must say the service Owners Manual provides was fast and efficient by being available online. The manual was in good readable condition and easily downloaded.
Thank´s for your help, I already recived these manual from you
Text excerpt from page 27 (click to view)
Installation
^ Secure the ducting to the mounting plate using a hose clip.
^ Insert the short edge of two spring clips into their slots from below and position so that the tab faces the center of the mounting plate. ^ Pull the power cord through the mounting plate. ^ Insert the four countersunk screws M 6 x 20 into the recessed holes from above. Tape the screws from above to prevent them from being pushed upwards when the nuts are tightened.