Chris,
On the unlikely offchance you wern't already aware, these may help

1. this website's historians may be worth contacting
http://www.h-g-canal.org.uk/index.htm

2. there are a couple of books on the subject, probably in your local library
"The Hereford & Gloucester Canal | Ledbury Railway" by David Bick,see extracts,
http://www.herefordshire.gov.uk/htt/628.aspx
http://www.oakwoodpress.co.uk/books/books_he-hu.htm

and perhaps less relevant in your instance
"Over & Over Again, 750 Years Of Change At Over" by Nigel Bailey, available on a wellknown auction website etc.

Hope this helps, good luck.