Could somebody please advise me on the suitability of this kit for a video camera.
I have been offered this equipment at a far lower price than buying a new K6-ME66 mic and I really dont know if this is a suitable alternative.
John
The K3+ME80 was the forerunner to the K6+ME66.
The K3 series used a mercury battery (PX23) and was discontinued when mercury batteries became illegal.
However - there is now a mercury-free version of the PX23 (available from Canford Audio and the K3 could also be powered from 12-48V phantom power.
The K3 series was discontinued over 12 years ago and so is at least this old. Is it black or "silver"? - the black versions were the newest (from about 1988).
The K3, however, does have a transformer output stage and was unsuitable for some cameras (hence the unbalabced K30-AV version for cameras).
I hope this helps.
John 
Many thanks John for clarifying matters.
Its experts like you who are our salvation.
John