Thanks for the guidance, bertsmobile. I went to the site, but could not find "Agricultural Parts" and then "Vegetation Management". I did find "Catalogues" and then "Slasher Blades" which seems to have quite a selection. I'm still going through the list to see if I can find one that is close to the size I need. I really appreciate the link because I have not found anything like these blades on any site in the US. I'll let you know what I find and end up doing. I hope your winter is not too cold down under. We are dealing with a really hot and dry summer here in MIssouri. My fields look ok, but the front lawn (about four acres) is as brown as dry hay. Been saving on gas, not having to mow. But I do prefer the lush green and fear for wildfires. So far nothing like Canada has been dealing with. Stay warm!
It is just a matter of knowing where to look
You probably will do better measuring the length between the blade holders to get the original length then taking them to a non brand franchise tractor shop like "Tractor Supply" which from what I see here seems to be everywhere , passing them over the counter and saying "got something like this that is at least X inches long ?"
We are going directly into drought again so it will be hot, dry & uneconomic .
Where I am it does not get very cold during the day time till the spring snow melt drops the air temperature to sub zero ( C ) in the snow fields and the westerlies blow this sub zero air with zero humidity right through you and because they have no moisture they go hundreds of miles without picking up much in the way of heat .
This fire season will be bad but next year will be another 2019 because we are too stupid to listen to the black fellas and do what they had been doing for 60,000 years before we shot / poisioned or just drove them off the land