During the WWI tjha Austrain army ordered the following boats
657 1919 Einschraubenmotorboote 60 13.00 2,.20 1,.05 0.600 fur k.u.k.Pioniertruppe 23
658 1919 Einschraubenmotorboote 60 13.00 2,.20 1,.05 0.600 fur k.u.k.Pioniertruppe 23
659 1919 Zweischraubenmotorboote 2x45 12.00 2,.45 1,.30 0.70 fur k.u.k.Pioniertruppe 20
660 1919 Zweischraubenmotorboote 2x45 12.00 2,.45 1,.30 0.70 fur k.u.k.Pioniertruppe 20
661 1919 Zweischraubenmotorboote 2x45 12.00 2,.45 1,.30 0.70 fur k.u.k.Pioniertruppe 20
They were completeted as the Polish Armerd Cutters:
657-> M3->KU3-> Soviets No.51
658-> M4->KU4-> Soviets No.51
659-> M1->KU1-> Soviets No.51
660-> M2->KU2-> Soviets No.52
661-> M3->KU3-> Soviets No.53

http://private.psi.com.pl/pmw/rzeczne/ku_1_3/ku_1_3.htm
http://private.psi.com.pl/pmw/rzeczne/ku_4_5/ku_4_5.htm

In 1920 some more perheps idntical boats were completed for the Romanian owners.
I think thye belongs to the same type. I will be very interested in any fates end eventuially pictures of them:
673 1920 Zweischraubenmotorboote S.R.D.I 2x45 12.00 2,.45 1,.30 0.70 fur SRD Braila 20
674 1920 Zweischraubenmotorboote S.R.D.II 2x45 12.00 2,.45 1,.30 0.70 fur SRD Braila 20
675 1920 Zweischraubenmotorboote S.R.D.III 2x45 12.00 2,.45 1,.30 0.70 fur SRD Braila 20
683 1921 Zweischraubenmotorboote VIKTORIA 2x30 12.00 2,.45 1,.30 0,.70 fur Nicolescu Tutracai 20
709 1921 Motorboote AURELIA 2x30 12.00 2,.45 1,.30 0,.70 fur Nicolescu Tutracai 18