Do you use a crank on your Excalibur? I might pick one up and I am even older than you.
I use a crank for practice, and when I cock it before I go into the woods. I carry the rope for reloads in the field. 260 pound prod, 130 pounds of effort with the rope. 12 pounds cranking effort.
The crank for the Matrix Bulldogs is pricey, but so is physical therapy and back surgery. I'm knocking on 68, and strains heal slowy.