eBay
3/16" x 40 TPI Coventry Die Chasers,  Grade S,  For 5/16" Coventry Diehead.

These dies are new and un-used but I have listed them as used because they have been stored for over 20 years and could be stained and/or miscoloured due to this

I have started the auction at a realistic price, These would cost 4 to 5 times this on a buy it now site.  90% of the dies I have listed are Alfred Herbert with the remainder being SKF.

Please note - The photo is not the actual set but for illustration purposes only.