Small fork with unknown makers mark

I have two slightly different sets of small forks - I will ask for help on each in separate queries - and thanks to the Forum for allowing people to get this info - New Zealand does not have a huge pool of expertise that I can tap into.

This first fork is Sterling, lion 925 marked. The makers mark is WT over RA. Leopards head means London, and dated 1839. It has the Queens head stamp, for duty paid.

Does anyone know who used this makers mark ? Could someone also tell me what this pattern is called ?

Probably William Theobalds & Robert Metcalfe Atkinson, it dates about right