Dnalr,
Have a look at :
https://docer.tips/aircraft-profile-...56-storch.html
At page 126 of the "Aircraft Profile" magazine number 228 about the Fieseler Fi 156 Storch, you can see a german unarmed ski-equiped Fi 156 ambulance from ww2 period ( code GA+TH ). At page 129 and 130, others are visble ( the last one is an export to Finland coded ST112 ).
Regards.