I calculated 1 zolotnik as 4, 26 g pure gold.
Number 3 indicates the tax was paid on 3 zolotniks, i.e. for 12,78g gold (pure or 14 K is the question).
If the weight was calculated for 12, 78 pure gold then 14 K weight would be 22 g but if calculated as
4, 26 X 3 the result is 12, 78 g. I cannot find any reliable reference of the calculation.
I have attached the image of the clasp. Red arrow points to rather unusual color of gold solder being white. Gold solder is always distinctively yellow. This is a weak point of clasps and they often break and need repair. On the other hand, unscrupulous dealers transfer clasps with lucrative marks. Cannot tell for sure, I am phobic with Russian silver.
Hopefully, other members of the forum will shed more light, particularly on calculation issue.