I have both a 1950s OM and a newer NM stainless. Both shoot very well altho I had to mess with the front sight on the newer one to get it to zero. They ARE picky about ammo; both of mine like Stingers about the best, although I've never tried them with pistol match ammo.
I used to carry the OM everywhere in my boot top (you can imagine what the bluing is like.....) and used it when I ate up all my backpack food. Many rabbits, a few grouse and chachlacas (pavo de monte), more than one trout (relax, the statute of limitations is long run out. I hope.). One rockchuck before I found out what nice diseases they can carry!
I have big hands but have always shot two-handed, so little guns suit me just fine. My OM has the original "plywood" grips, refinished a few times tho.