Hi Keith, Bolts and hardware are gettting harder to find every day unless you want to use metric. It makes it hard to keep everything at a standard without drilling out and replacing every nut and bolt.. So could l suggest that you should get in touch with the following.
CLASSIC FASTENERS. PO Box 187. Welland SA 5007. Australia. Tel: +61 8 8346 9838 ...
www.classicfasteners.com.au
They have helped me out to no end with 2&4 BA bolts and nuts for my project and they have a good catalogue that you can download.
Rgds
Steve