The Deerfield had an interesting folding rear aperature as did the Ranch Rifles. Folded, they allowed a scope bell lots of room.
As a rule, the XS peep sets very high, so much so that the corresponding XS front sight is typically much higher than the factory original on most rifles.
Only speculation, but I doubt if there is enough room for conventional scope over an XS rear peep. Again, this is only speculation. Heck it may work, or youi might get it to work with Ruger x-high rings, but I wouldn't hold my breath.
What might work (with factory std rings) is a short tubed dot scope, of such a length that the rear bell is forward of the rear sight. Another option (if available) would be Ultimak rail and mount the scope forward in scoutscope fashion, with detatchable rings. Dunno if the Ultimak makes a rail for the deerfield.
I've got an early tube feed Ruger .44 carbine with XS's, and there is no way a std scope bell would fit over my rig. But the Deerfield is different of course.
You will like the XS-s, but they are not cheap.