Thanks for the pictures. There's no stainless plates on the hull?
You could try deflating the rib collar to see if there's any work on rail where the tubes attach near these points.
Again it's difficult to tell, but normally with these lifting points you have a spreading plate on the reverse, penny wachers, nylock nut behind the U bolt. On a transom you also have the security of going thorough plywood, not simply attaching to fibre-glass sheet into a void.
Is that with or without VAT?