That is strange. mtl_specBump works fine for me with solid objects. You may want to try that a bit more, since txesmi mentioned this would be a much slower way to render objects.
@txesmi The first version worked great, but for the second (specBump2) I can't run it with the "technique = "SpecTrans";" or "technique = "SpecSolid";" lines. It works fine if I comment out these lines, but my version of gamestudio does not recognize the "technique" command. At least not where you have placed them in the MATERIAL* definition.
When I comment out the lines, it does seem to work fine though, but I'm not sure if it's working as intended...