I've been working on elements for my game, and looking through demoscene stuff to get inspiration for some of the SFX I want to use to tell the story with. One of these things is flat shaded 3D models, which I have an affinity for - they look incredibly oldschool, and I do make 3D models as well as pixel art. I know flat shaded 3D prims are possible in AGS, the AGS3D module/plugin is testament to that. Unfortunately, that module/plugin only does 16/32bit, and my game is in 8-bit. Being 8-bit, it also brings up the problem that any shading can't rely on just RGB values. I've been thinking about this, and I think if I hardcode what tri is coloured what palette slot, I may be able to produce 3D images within the bounds of my game's limitations, like so:

The black outline is so that the image can be seen even when the model is turned at an angle, since in this shading model, we wouldn't have the luxury of actual shading or lighting. But because of the lack of actual shading, I can also get away with using less polys for everything. I'd guess the flow would be like this:
1) Load OBJ model
2) Have an array the size of the number of tris in the model, with assigned colours to them
3) Draw the model using the assigned colours onto a full screen drawing surface.
4) Duplicate the drawing surface, have a completely black sprite, and cut out the model's dimensions with CopyTransparencyMask.
5) Draw the sillhouette 4 times, at offsets (0,-1),(0,1),(1,0),(-1,0) onto a new drawing surface
6) Draw the final sprite onto the drawing surface at offset (0,0).
But I'm not actually too up on the programming side of this (I'm an artist :<), and I can't find any old versions of the AGS3D module (the one that uses DrawTriangle) to test it out.
So, how easy would this be to do, and more importantly, would it be fast enough to run real time? I don't need any fancy texture mapping, or lighting, or even high polys, I just need to be able to rotate, scale, and position a model in 3D space. Where would I begin to do something like this?