For a red recoil pad you may look at Silvers. Kynamco in GB stock them.

At the same time you could order some Kynoch Nitro Express wads to use with powders not giving Close to 100% fill. I use them in my 500/450 3 1/4".

They might also sell you some cartridge cases?

http://www.kynochammunition.co.uk/silvers.html

Cheers, Chris