Yes, Rover has a long history with 2-strokes. But even from the 1960s it is clear that most Rovers would be 4-strokes. Note that the Model 26 was designed as a 4-stroke base; and an adaptor plate was used for the 2-stroke models; whereas, Victa made separate bases for their 2-strokes and 4-strokes.
I lover the 6-digit phone number for Rover's factory and head office. When the high-arch machines entered the scene, Rover would continue to use the Challenger base for store brands - like the Powermaster... By that time, the factory phone was 7-digit.
I'm guessing that Bris-Vegas changed to 7-digit phone numbers in the early 1970s (?) ---------------------------- Jack
