[The Saw Set Collectors Resource Shows 2 versions of that sawset, yours seems to be the later version with a pin rest, the earlier version has the rest as part of the lower handle.
There is no specific patent listed, tho Morrill has quite a few patents, so probably one or two of them apply indirectly. The #5 is listed as the largest one made.
Looking at your photo the tooth size seems to be in the neighborhood of an inch, so it's likely for fairly large blades, but not gigantic blades, like a sawmill. There is a limit to how thick a blade can be bent with a plier type set, above that you need a giant wrest, or a good old fashioned hammer...