I wouldn't necessarily treat this as some sort of fake. From the publications on Dartington they were known to have produced cobalt blue items in 1974 and then again in 1994, the latter being earlier "Recycled Designs" made with recycled crystal.
Assuming it is 5.5 inches tall, such smaller Greek Key vases did not have polished out pontil marks and the slight variation in the pattern may simply be reflective of the use of a later mould.
I have seen several items which have deviated from the published "standard" Dartington production colours, not only these small Greek Key vases but:
An FT88 Hexagonal Candleholder in cobalt blue.
An FT52 Ugly Head vase in cobalt blue.
Daisy Dishes in green, (when the books say they were only produced in clear or grey).
I'm sure there are many more examples out there.
The good news is that the small cobalt blue Greek Key vases tend to make more than the kingfisher blue ones on e-bay, but still considerably less than Flame red examples.
As to the design, each to their own, but I quite like the geometric shapes coming out of the UK in the late 60s!