Yes they are, so you know who produces them! The convo is one that I can easily repeat,provided I can get the base materials. Do you think there would be an interest? The one shown does have overlapping blades but they could be widened out for other tractor wheel spacing. The Fergie has 50 inch centres which gives about 25 inch rows. Main crop are 30 in spacing which would suit a 60 inch wheel spacing. These blades are at 43 mm centres (outer blades) which gives a 1.5 mm overlap on inner and outer sets. Hope this makes sense.