If they don’t have bolts available in the size you want, you may be able to get threaded rod and nuts, and have a machinist weld the nut on the rod and cut to length.
Are you sure they are Whitworth thread, with rounded crest and root? Or is it just the pitch count? I think C&P kept to older patterns when SAE standards were adopted.
You could try https://britishfasteners.com
If they don’t have bolts available in the size you want, you may be able to get threaded rod and nuts, and have a machinist weld the nut on the rod and cut to length.
John
Are you sure they are Whitworth thread, with rounded crest and root? Or is it just the pitch count? I think C&P kept to older patterns when SAE standards were adopted.