Hi Paddy,
If you don't get things graded, it would be best to send it to someone like https://www.thenumistacker.com/ who will handle that all for you. He deals with all sorts of coins and sends them off to NGC for grading on your behalf. Here's a video explaining what he does.
The cost of the grading depends on the value of the coin really. The charges for the categories differ, as some are more valuable than others, and others need more research. You're probably looking at around £50 odd to get this graded with NGC, but his charges are detailed on the website.
The worst that can happen is that NGC refuse to slab it as "not genuine", in which case you've lost your money, regardless of whether they plastic it up or not. Having it graded may make it easier to sell on somewhere like ebay, but it's a crap shoot half the time on there. Difficult to tell what grade you'd get, but looking at the others on ebay, you might get an MS60 at best which roughly equates to EF to gEF.