Sled to Tow behind snowmobile

[hazelnut]

Can someone guide me where to go and get the actual hitch for my snowmobile. I have a homegrown trailer that was given to me by a generous neighbor. The trailer is a wooden box mounted on a steel frame with metal snowmobile skis. The metal bar has the pin through two holed, (more like a bolt and nut). I need the actual hitch that mounts on the rear bar of the sled.

Any help, links, photos, advice will be most appreciated.