ISA fix replacement clamps

We have bought a second hand Vetura Cadet awning and tho it has fibre glass poles the clamps are butterfly type.

I have seen Isabella sell replacement ISAFIX clamps which they say are easy to change.

Has anyone tried to change them and are they worth the £50+ cost?

Also Vetura now offer a replacement conversion fixing similar to the ISAFIX which runs out slightly cheaper but not convinced it would work as well.

Comments gratefully accepted