Thanks everyone. While looking around I found some couplers on ProMags site.
I know they have a some problems and reviews on their magazines, which I do have a couple and they work for me. I saw the couplers were made here in USA, so giving them a try. Should be here this weekend.
If they don't work, I'll let y'all know.
EDIT 10/25:
Got the mag couplers from ProMag. Seem well built/polymer and have to use (2) couplers per the staggered magazines to help with the weight and not let magazines sag to an angle when storing or while under recoil, like they do when taped together with a wood block between(for those DIY mag wraps). I like that. You get (4) couplers per bag/order, so order several bags if you want to do more than two coupling of magazines. Lifetime warranty and #PM016B. Made for AR15 and Mini 14.
Good tight fit on the magazines and the coupling screw is made of steel and anodized in black, BUT one thing I thought of, is when under recoils, the screw might back out some, so I'm gonna get a few nylok nuts and cinch down to hold that screw in position to not back out at any time.