Short answer: No.
Concerning the textures, they appear to be regular PNGs, however I haven't found a way to open them at all, same goes for the models which again appear to be Direct3d Models (.x), importing them into blender neither puked up a failure nor a model. I'm not sure whether this is due to different Character encoding (who knows, maybe someone running on a rig with japanese character encoding wants to give a try?) or some other reason.
Of course the graphics are only half the problem. If you really wanted to create a new mech or modify an existing mech you'd have to mess with the various files that define the mecha in the game logic, I have the vague idea that the .hod and .spt files got something to do with that, without any info from the developer there's no way of getting anything done in THAT regard.
All this info is based on my own empirical experience, coming from messing around with the game files a little for about half an hour so if someone got more indepth info, just disregard my little rant and post it.