The owner's manual/operating instructions that I purchased was the original factory document and it was in at least three and maybe more languages. I no longer have it because I sold the tape recorder and included the owner's manual/operating instructions and a service/repair manual that I bought on ebay for the new owner.
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.
Great price, Quick delivery, the document was very usefull A+++++++++++++++
Text excerpt from page 18 (click to view)
Removing the TRAMECHA Assembly (Refer to Figs. 6 to 9.)
Remove the CL. base assembly and tray. Reference: The TRAMECHA assembly can be removed without removal of the mechanism board. 1. If the TRAMECHA assembly is lowered and it is TRAMECHA located out of the PLAY position, turn the idle gear assembly in the arrow-marked direction so that the hole in the part f of the tray gear meets the hole on the CL. base assembly. (Set the TRAMECHA assembly at the PLAY position.) 2. Remove the three screws B fastening the TRAMECHA assembly and then remove the TRAMECHA assembly upwards from the front side.
3. At the same time, remove the spring from the groove of the CH. base assembly in the part g of the TRAMECHA assembly. Part g Idle gear
Note: When reinstalling the TRAMECHA assembly: Check to see if the spring is properly engaged with groove of the CH. base assembly in the part g of the TRAMECHA assembly. After making sure that the three insulators of the TRAMECHA assembly are properly set on the bosses of the L. base assembly's guide, fasten them with the screws.