There are lots of people on Etsy who will create a branding iron for you. -- This is the one that T got me for christmas.

(expensive but fancy... CNC?)

Or, how to make one yourself:

• https://www.youtube.com/watch?v=tpHTSr4rKsE
• https://www.youtube.com/watch?v=vEyTCOIcMIQ
• https://www.youtube.com/watch?v=yTUQoCpCDTM
• https://www.instructables.com/id/DIY-custom-branding-iron/

Oh! You can make one by casting, of course!