Suffolk super punch 17" info needed

Hi all, I have recently purchased a suffolk super punch 17" for spares or repairs needing a fuel tap. From the images i understand they use a cast iron 98g14 98cc suffolk engine?. I know my way around these engines as i have the same engine in my westwood gemini rotovater which unfortunately the cylinder cracked. I am thinking as ideally i need a rotovater and lawnmower, my plan is to swap good bits as gaskets, seals etc etc were all brand new for the rotovater which has the broken cylinder. Then i can simply disconnect the engine from the chassis of one or the other and either rotovate or cut the grass with one working engine have a spare engine for parts . Only issue is.. im not familiar with the suffolk super punch lawnmower at all. It has a handle to engine and disengage and ive seen a video of someone moving what appears to be the clutch drum or something?. Can anyone supply any information on age and how to use?. Thanks Rob