Iron ore railway maps in vale of Belvoir, Leicestershire?
Answers:
I lived in Belvoir for best part my life and I remember the old railway being taken up. A large section of it follows the route down to the Grantham Nottingham canal where the ore was barged into the towns. Now, that part of the route is a cycle, walking path.
If I were you I'd go to the Estate Office on the Belvoir Castle estate. (The phone number is in the book) The old iron ore mines are on Belvoir Estate land and they have extensive maps of the area. Ask if you could either study them, or even have, or purchase a copy of them.
The other places that may have records are, Grantham Museum in the old Library building on St Peter's Hill, right next to the Guildhall, and the library itself which is in the Isaac Newton Centre. If they haven't got what you want, they will get it for you.
I hope that's helpful.