Yes, this "fake" Yuko is still with me, it has a weak, spreading growth, no flowers this year.
Fruits in November 2017:
Nobody actually knows what it is, but originally it was brought under the name Yuko from the former USSR.
Several interesting hardy hybrids were produced over there by crossing and backcrossing of lemons with Yuko and Ichangensis.
I believe most of them are lost now.