Hi Simon
There was a thread a few years ago about RND badges which were most likely original but weren't Gaunt made, I'll see if I can find it.
I would not like to say either way whether yours is good or not but here are some comments. Firstly, the ship is poorly made, I would expect it to have far better detail. Secondly, there is reasonably crisp detail in the reverse, but only in the areas of the crown and scroll at the top, and the globe and scroll at the bottom. The wreath detail on the back is not nearly as crisp which raises a question mark.
There seems to be a similar one on sale here:
https://www.ebay.co.uk/itm/The-1st-D...gAAOSwT~9WiBXC
Cheers,
Alex