[DESPERATE][NON-SH] Fast hand-painted-style low-poly textures?

I’ve been asking this question all around the Internet so I decided to ask it here as well.

I’ve bought a set of models from BitGem. An indie developer made a game with a level editor. I used the BitGem models in custom levels. Now the developer wants to include my levels on an anniversary CD which should be released in like a week and licensing problem occurs, because they don’t have commercial licence for these models and BitGem licence says models should be embedded while custom levels use plain 3DS files.

The only solution I see is to provide replacements for these models. So my question is: do you know a way to create hand-painted style textures for low poly models (I’ve already made the models so their dimensions allow me to replace the BitGem ones), fast? The models I want to replace are a part of Mayan set by BitGem: Low Poly Mayan Temple - Bitgem

This artist says in their description they use Lightwave 3d for their final render.

This one did the work on Blender, but it’s “painted” texture, not hand painted persay…

I found this: texturing - How to get a smooth curvature map from a normal map? - Blender Stack Exchange

Now the question is how do I sculpt the models to get a nice normal map. Maybe I know someone who has access to ZBrush…

I use this for free stuff https://opengameart.org/