I'm amazed at how this occurs, they're made from the same extruded belt, it's not the dealers/shops fault, but alas very very common with this, not just on cossies.
When I worked for FKI we made things like this, it's made from a massive wide belt around 1 meter wide put on two rollers to spin it, whilst a series of blades cut into it, to make it into strips, a lot are made by I think now by Northern Rubber near notts ?
tabetha