I am not sure this is what you are looking for but CR Hill makesgreat stamps, and have most hallmarking stamps in stock in straightand bent shank.
Just give them a call and they will order custom stamps for you.
The one I saw last did a security stamp with very small letters formarking tools & house hold items. They also would make custom marksto put in hallmark pliers.
I finally found the company it was microstamp.
Thank you all for your replies.Regards Phil