I was a bit bored tonight so I had a play with your discarded map. I think you discarded them too early. The dark mountains looked just fine and inverted made a great height map as a starting point. I also made a black and white sea only map so that I could drop the sea away a bit.

I loaded these into my GTS app though I reckon most of the terrain apps like Wilbur would do just the same. Then I added the height map and lowered the sea with the other one.

Then by erosion and some use of rivers and so on I progressed it up. I did not pick where these rivers were placed I got the app. I know that many people here have been using Wilbur to do that job real well. Anyway, after a while I got it to a stage I was happy then applied some textures to it.

Et voila...

(Color and height map attached if you want to play with it further).