The set is what I would call Queen Anne style, which has been very popular in many parts of the world for at least 150 years (surely much longer in the UK). The fluting forms a heart-shape in the center, which I have always thought of as a 20th century variation, although I am not an expert in this area.
One possible candidate for country of origin is Japan, from immediately after WWII. I have seen several teasets marked "sterling" or "sterling silver" only, with no maker's or national marks, that were thus identified from provenance or from original packaging. However, most of these sets were either in a very plain modern style or included some Asian element of design. For instance, see this post:
http://www.925-1000.com/forum/viewtopic ... 13&t=34406
That a very hesitant hand seemed to need a lot of practice to mark the piece as well as the rather light stamping also supports this theory of immediate post-WWII Japan. The Queen Anne pattern, on the other hand, does not lend itself to this theory.
Another possibility is that the set was made in Hong Kong but for some reason, never fully stamped. Unfortunately, without additional marks or provenance, the origin may never be known.
Regards,
David R