Great thread for me, I’m in the same boat at 65.
I use a strap that can be worn as a harness but I double up the two straps over my left shoulder so it looks the same. I think it was mentioned above. But the big advantage for me is that it also fastens around my waist, relieving my back of much of the weight of my bass. (I untuck my shirt so it not visible to the audience.) Someday I might need to use it as a harness but not yet.
I use a strap that can be worn as a harness but I double up the two straps over my left shoulder so it looks the same. I think it was mentioned above. But the big advantage for me is that it also fastens around my waist, relieving my back of much of the weight of my bass. (I untuck my shirt so it not visible to the audience.) Someday I might need to use it as a harness but not yet.