dually wheel mechanism type identification

[towbar]

I have a pair of duallies that I got with my Dx-6.05 tractor, the plan is to clean them up and sell them. Is anyone familiar with this type of attachment mechanism? Is it popular? It looks well done, does it have a name'?

Link of my ad: https://www.kijiji.ca/v-view-details.html?adId=1647913815

TIA

 

[56wrench]

I’ve never seen that type of mounting before. It must be European?

 

[towbar]

I think my tractor was built in Germany and sold in Holland before being imported to Canada as a used tractor. That mechanism is good design, quick to install/remove and I think extremely strong. Works like bulkhead doors on ships and subs, I don't think the dually would come off hitting a wall at a good clip, unless the HOST rim got deformed. I'm having the tires removed already, will have a better look at it when I can turn that rusty handle

Picture was probably original dealer decal