If this is indeed possible, somebody please let me know.
Currently, this has not been touched by anyone on this forum, from what I understand.
If I find a way to do this, I shall tell.
What I do know, for now, is this - somebody made an updated model for Diamond Weapon as well as Ruby Weapon. I am not sure how this was done, other than hard work and tons of conversions. Blender may have been used.
If the user on this forum that made those two converted models would come forward and reveal the process, that would be most helpful.
According to what is listed on The Big List of Mods made by @PitBrat, @Grimmy was the maker of the World Map version of the updated Diamond Weapon Model. I can not confirm this at all, unless another member does so for me.