Hmm, whats with the nationl insignia? :P
Thous, its nice to see such details as Ps registration codes, even thou, in this case, its not right ;)
The setting of "Ps-tunnus" is: type serial (determined by the vehicle type, these are bit hard to find, but fex. "The Finnish Armiured Vehicles" by Esa Muikku & Jukka Purhonen does include list of these) - vehicle number in oreder of registeration.
So, in case of T-26 model 37/39 (as in here) the number might be written as "Ps 164-13" - the 164 is the type number of that model, 13 is the number of tank. Should also be noted, that 161 (as used here) refers Vickers 6 ton medium tank, also used by finns, but notably different from T-26 lates models.
Allthou painting is clean, and if we forget the odd national insignia, it will propably go nicely on tabletop :)
Greets, Antti.