I used one almost exclusively when I was to wearing a suit or a sport coat every day . I was carrying 4 and 6 inch N frames . I had a model 19 and never carried it concealed . I had some fairly decent leather ones made by a saddlemaker I knew . The synthetic materials I did not like , but I may not have spent enough time adjusting them since I thought I knew the first time I put it on I would not quit using my leather . For driving I still think they are the best . I never really tried to conceal the shoulder rig in light clothing , might be rough .
A minor thing was I always conscious of the weapon in shoulder holster , more than my belt rigs , but maybe that is good .
I can not carry the same big guns at all on belt rig and and drive or conceal them . I don't remember the model number , but I bought my partner a 9mm S&W semi-auto that looks like your 4043 and a nylon shoulder rig , he loved it and was wearing it the last time I saw him as I rode into the sunset of retirement .
I will get a Lawman Dirty Harry if I keep thinking about this and start packing my mod 29 again .
I almost forgot , This sounds kind of dumb but when we started with the shoulder rigs we put them on and follow each other around and we would stand up , sit down , bend down, reach and every thing we could think of and only by looking at the other guys rig could we tell each other when we were showing .and where the straps were slack to adjust . If I had been alone I probably would have given up before I got it right .