It replaces it.
So it's an RS with new swivel studs.
Just as it was advertised as on Proxibid.
There were aftermarket modern Savage 99 studs made that used the front screw attachment. They were easily found. So the fact that it has them doesn't prove it's an RS.
If it doesn't have the right studs and peep sight, there's just no way of being sure. It's hard to fake a 99R to 99RS because those flat topped studs are hard to find - not impossible, I've seen a couple 99R's "converted" to RS configuration but obvious because the buttstock stud was in the wrong place. Most of us just go with 99R when the sights and studs aren't there.
