The tag at the bottom looks like one on mine and with the nuts on top to bolt the manifold heat shield to I would say it's a miltek 421 manifold (original Frp )
Although someone will be along who could offer more help.
Thanks for your reply.
I was told that it was an original FRP item. I just wondered what the number was for. I will get the rest of the system soon, I needed to know what would fit on to it.