G'day Dandare ,

The first one is a Rapier rotary mower introduced in the mid-1950s. It was originally powered by a Vincent two-stroke engine.

https://www.outdoorking-forum.com.au/forum/ubbthreads.php/topics/111586/farmfitters-rapier-c1950s.html

The second one is home made ,although I see a lot of people on other sites say it's an mower made by Indian motorcycles but
that is incorrect, it's just a DIY mower.

https://www.homecrux.com/diy-lawnmower-built-mimic-vintage-cars/66537/

Cheers
max.