being left handed it is kinda hard to find things like shell holders that you don’t have to drill holes in your stock. so I went down to my local gs and bought an ati universal shell holder. took some kydex and rivets and made this guy. turned out great and best of all it is out of my way while shooting
I shoot long guns leftie also…
Good idea!
That was some very good improvising on your part, excellent work…so long as it can’t come apart on you when needed most that is. 
In all seriousness if they are nearly impossible to find then consider producing them at home and sell them on gunbroker or other venues. If they’re that rare and well made you can eventually find a small manufacturer and take them to market.
I thought about it, but unless I were to get stocks from different guns I could only make them for the guns I own.
One problem with I’ve found withstock mounted holders is they limit your ability to shoot the shotgun support side.