Pretty sure Ruger won't touch this one as it was not a factory offering. I think Bowen used to do them (at least the 7.5) but gave it up do to too many "crooked ribs" that were fine for sights but not for cutting ring slots into. This may have changed, but it is what I remember.
PS I think both rings would have to go in front of the turret (5.5) in order for the scope to be safe from muzzle blast.
you can also drill and tap the top of the barrels rib...either way ,it will work...a know of no one right now that offers the milling out for the Ruger type rings as said above ,too many issues as to things NOT being "square" with the rib/barrel/bore............... :roll:
( not to say it cannot be done, but at WHAT COST, by a GOOD machinist..)?
Of corse, the other option is to buy a RH-44R and cut the barrel down to the length you want...
What caliber is your Redhawk that you are thinking about hacking into? There have been a number of these used "R" models listed on the various auctions and some have been going pretty cheap in my oppinion.