I'm a 59 YO with some old injuries coming home to roost. At 5'8"/175ish not a burly fellow either.
I've carried/concealed a S&W Mountain Gun and am fixing to tote a Mountain Revolver as soon as I acquire the holster.
Adding a set of Perry suspenders has made all the difference, for me. I'll probably use my Wilderness belt and a Lobo or Rosen pancake this go-round. Between the suspenders and belt, I can set the rig just where I want it, snug, but not uncomfortable.
I usually wear a t-shirt with a square-hemmed, untucked shirt over that. Works fine and so far, none the wiser, including many LEO friends and associates.