Years ago (about 35), I had a shoulder holster that held my smith pistol upside down under the arm pit. It was made of black cloth material and had a strechy material across the top of the frame that held the gun securely in place. Not sure whatever became of it, but I would sure love to have it back; it was not expensive and it work better than any I have seen since that time. All you had to do was pull it down and forward and it was out and ready for use.
Anyone having information about this type of holster, please put it on the forum.