The catalogue I mentioned can't be reliably used for plating 1d blacks or 1d reds.
The two websites you will need are:http://www.gbps.org.uk/information/...tion-sheets/
Even between these two sites, not every stamp is covered.
For the first website, follow the links on the left side of the page.
For your OG stamp, I think it's plate 58, but would welcome Maiden's input. Cat.value £40