Right, well the good news is that I received it (after fun dnad games with UPS) and it looks like the right part!
Although, in the packet looked fully extended. I opened the packet an the pin fell out:
It seems to just "sit" in there, so I thought ok, not a problem, nothing has leaked out.
However, when I push it in, it does go in a fair way, but then springs back out when I let go and sits like that:
Is that normal? It feels almost like there is air trapped in it springing it back out. Will be be ok as it's under a strong pressure from the spring? I can push it down with finger pressure as below:
