If it were the old TRS model, you could jsut do what the above guy did (And me! I did some light sanding on the sides of the cavity to fit an Edge in my RG470) but since it's the Edge Pro II, you really cant replace it with anything.
They moved the posts forward, or backward, I forget.
But they moved the posts to a different location, and the Edge Pro trems reflect this and have an altered saddle placement to accomodate it. Unfortuantely, no other trem uses that layout, only hte Edge Pro and Edge Pro II.
Basically, if you want to upgrade your trem, you're gonna have to buy an Edge Pro, and rout out the back of the cavity on yours by a pretty good bit. Maybe 3mm deeper along the backside? When I say deeper, I mean extending the cavity toward the back strap nut. Becuase the Edge Pro's are longer than the Edge Pro II. No doubt intentional, to prevent this sort of thing.
I say if the trem seems to be working well, then just buy some locking studs for it and you should be good to go.