Still life signed "Franz", see which of Franz?

[Agatha Gregson]

Dear friends, the
This still life (oil on canvas: 34H74). Signed "Franz" in the lower left corner (three left photo).
Which is, in your opinion, from a family of artists from St. Petersburg Frentz?
In my opinion, this is very similar in style to the database presented in this urban landscape Rudolph Rudolfovich Frents, "lighted up" on sovkome. I spread for comparison (right two photos). Like? However sovkomovskogo Frents paint cheerful, bright, contrasting ... And contrary to our Frents muted colors, dark, depressive. But it is possible and combines them? After all, in either case, the artist uses his palette to convey your mood?
However, the signature in the two samples are not very similar - just like the letter "u" with the final stroke of ...
Or perhaps it was the younger of Franz, Vladimir R., one that traveled to Kamchatka and wrote about this children's book?
Maybe this is some Frentz number 4?
I would be very grateful for your expressed opinion, because I do not think that this still life worth the cost of examination.