There is one for sale on eBay but they want £150. I have a friend that repaired one for me, and he might do another one if required. This does require the old one sending to him. I probably will see him at a classic car show this Sunday, so I will ask him if it is ok to pass his details to you. The one he did for me looked stronger than the original design. I think he would be looking at about £30 + postage.
My friend will repair your catch for £30 + delivery, so please contact me if you want one doing. I carry no responsibility if there are any issues, but I can only imagine it could only be delivery problems as the quality of the one he did for me was first class, and in my view stronger that the original design.