>Somebody in the past cut the jaws off ...
That type of wrench seems inappropriate for tight places , even with the jaws shortened, however, the sawed off jaws might allow you to hammer the wrench onto a stubborn nut, common practive with traditional type monkey wrenches...
Or perhaps it's owner simply wanted a traditional monkey type wrench...(If the jaws had been badly damaged already it would be a sensible 'improvment' to the wrench....)
I have a large german made double jaw wrench around here somewhere (twist handle) , it is very kewl looking, but, I have never been able to figure out what the advantage of having 2 jaws exactly alike was supposed to be...