That's a good start.

My guess is : mix between Australia and scandinavia, with the lofoten and north coast of Norway in the NE, the gulf of Botnia in the middle and the Finland coast on the south west. I kinda like that because I used to do the same : mixing some earth parts to obtain a nice landshape with a "believable" feeling
In fact, I'm still using that kind of inspiration, but more with the paleogeological maps.

As Triplicate, I'm wondering what is the meaning of your gray shading.