VLTOR Metal Receiver Question Concerning RAS

[Firewalker]

I'm thinking of installing a RAS on my standard VLTOR metal receiver and I'm wondering what brands fit.

I tried searching but couldn't come up with anything except that there's a chance that G&P made the VLTOR metal body (which would answer my question if VLTOR would ever answer their email to confirm or deny).

I -had- a rail system I bought off of here (custom milled, really nice) but it just doesn't fit on my VLTOR receiver, so I'm kind of apprehensive about investing a chunk of change into a rail system. Don't want to buy one only to find it doesn't fit.

EDIT: Forgot to make it clear that this isn't the MUR, but the vanilla metal body as seen here. Just hope to not get any wires crossed to make this as quick as possible to answer.