This little 1/2 size db

[Pino Cazzaniga]

Here is a little bass I finish to repair 2 weeks ago.
I have no clue about the "who or when or where" of it.
Did somebody see something similar?
The front is 6 pieces spruce, the back, sides and scroll plain maple.
The linings are beech.
The flat back was carved inside between the bars and outside to make a channel. The purfle is strangely 7 sheets made.
The string length is cm 95,5.
It was originally 3 strings.
Thank you for any idea !