There's good news and bad news ...
Good news 1: Received OK and they are the correct item.
Good News 2: Fitted three of them OK - But they are a very tight fit in the housing.
Bad news: They are so tight to fit that, while fitting the last one, I was just a bit too impatient and the pitifully-thin plastic housing went "POP".
"Oh Bother" - I said.
So - The araldite is now setting - And when it's set, I'll beef it up with body filler. That should do the trick.