vacuser
Thank you! This machine, then, would be just as old as your 606 with the Mercury shake-out bag.
The serial # on both your 606 and 606A can be found on the back side of the nozzle by the front wheels (1971 and later) or on the underside of the motor unit between both wheels (1970 and older).
Example: Serial No. 67G-E-59813, Amps 3.0
Thank you,
Benjamin "Ben" Edge