I recall a range of clip together kits which included a motor and batter holder. These were in the UK in the mid 70's
There was a P51 Mustang (non-bubble cockpit variant) . The Plastic was in two shades of brown and the kit spun the prop and possibly powered a tail wheel.
Also I recall a Gray & white plastic MTB in a smaller scale that could go in water and had powered props.
Possibly a Tank and a Cessna Floatplane too.
I half think they were Scalecraft or Minicraft ? Can anyone remember the range and any others in the range