Veneta Door retainers

JayEss

I've just replaced the rather old looking retainer with a brand new one to find it's about as useless as the original.  The slightest breeze will cause the door to swing. 

We used to have a knob on our Bailey which held the door in place but that's not possible anymore as the door is too thick.

Does anyone else have this problem?  Even better a solution?