The "reject" measurement for ring gap is .035", HOWEVER...
That is done with a brand NEW standard bore ring, not the OLD (and worn) one you have. While the .050" you measure is well out of specs, using the OLD/WORN ring will not tell you if it is just ring wear, bore wear, or BOTH. If indeed that is a 5HP Briggs engine you have, there is NO WAY the bore would measure (only) 2.4625", which is SMALLER than original/new! Either that is a typo you posted or you are not measuring accurately with precision instruments. As far as the part # you provided- Yes, that is the correct # for 5 HP chrome rings. Evidently, some "other" rings were misplaced in that package at some time. Basically, you got screwed. (Been there, and had that done to myself on a few occasions).
Michael