Kolonial Kanonenboot 39 Entwurf "K", 19??
It is not clear to me what this ship was or was meant to be. It is possible that it was intended as a design for finishing the captured Dutch gunboats eventually called K1-K3 in German service. It is likely not the captured Belgian ship which later became K4 in that it lacks the extended upper deck of the K4.
The pencilled notations on these plans may have been made by Russians who captured them after the war, and their use of K1-K3 could be their own guesswork (but then again, it could be right).
Michael Meyer (username mikemike through cityweb.de) writes to add:
Concerning the Kanonenboot 39, I read the information in a Podzun/Pallas publication about the Z-Plan and other long-range planning of the Kriegsmarine which I unfortunately haven't been able to find when I went looking. It was definitely an official project of the K-Amt (Navy Design Office), but I doubt it went beyond the prelim design stage. Certainly no contracts were ever let. I'd guess the type was too specialized and too expensive to make sense in European waters. As I said, long-term planning (or, perhaps, more accurately, dreaming). You may know that the Kriegsmarine had a wish list of naval bases it wanted to acquire literally all over the world (Azores, Falkland Islands, Caribbean, East and West Africa, Micronesia) after the war was won. This is in the same vein.
Ton Tanke contacted me to offer a different interpretation than the above (I have edited his comments):
Regarding the use of the words Kolonial Kanonenboot I think the name has nothing to do with "dreaming" on the part of the Germans for how they would protect future colonial holdings. The ships were originally designed for the Dutch navy. The main task of the Dutch navy before WW2 was not to defend the homewaters, but the colonial empire in Asia and the Carribean. I haven't seen the original Dutch drawings, but my guess is the Germans just translated what was written in Dutch, and the ships were designed from the outset to serve Dutch colonial protection interests.
You can find design studies of K1-K3 on my site here.