Have you tried final bosses' heirloom models mod? He has retextured almost all the weapons and it even shows heirlooms as looki more unique and quite visibly different than the originals. Quite a few of the retextured models in my opinion need to be redone or improved but he has done an excellent job in make a lot of the models much more aesthetically pleasing. It's definitely worth a try and you can always take it off it's not favorable for you