Tassie Dan, there is this one in NSW
https://www.ebay.com.au/itm/Vintage-Rare-Atom-Mowfast-Mower-1950s/264661122442?hash=item3d9f083d8a:g:OhwAAOSwa29eVxKi&frcectupt=true hope the link works, $150.00 he seems to be a bit of a dealer he may pack it up for you if you can arrange to have it picked up.
Still think it will be cheaper to 3D print the parts.
If you can supply me with the dimensions between myself and a mate of mine in Qld we may be able to do it for you. There are 3 of us novices at this stage one in WA one in Qld and me in NSW, corresponding via email, the chap in WA has the printing experience (4 years at this stage) the chap in Qld is doing the designing on a CAD program and we all have a go at printing and give each other feed back.
So if you had a drawing or photo with dimensions I am happy to have a go for you, let me know.
Beech