Hello Hermee, Bruce and all

My best guess is that this is a Model 7110 or 7113.
The former had a 10 Series Briggs; the latter a 13 Series Briggs.
These were named as the Colt Minor and the Colt Major.

This is an early model Colt (but not the earliest model).

Note the steel seat base.
This means that the seat, itself, was foam bolstered and with
a red-coloured synthetic cover. This would be first half of the 1970s.

https://www.outdoorking-forum.com.au/forum/ubbthreads.php/topics/85061/rover-brochure-c1973.html

The Colt was probably introduced alongside the Rancher in the
late 1960s.

The Foote gearbox needs a careful service.
https://www.outdoorking-forum.com.au/forum/ubbthreads.php/topics/78420/Rover_Colt_Gearboxes_Service_I.html

Hope this helps.
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Jack