LOL...hey, first hit is free
OK, to answer the questions:
1. The cord on the barrels is done in a way very similar to how japanese swords are wrapped...I can''t recall the actual name (sorry!), but it is a royal PITA to do....took me probably 12 try's to get it close to correct the first time, now I can do it in my sleep
The sling is done in a survival braid. Cut that loop of tan cord at the base, and give it a pull. The entire sling disintigrates into one stupidly long cord in about a second. Something like 40-50 feet.
2. The side saddle: I bought this weird plastic at a surplus store once. It machines like UHMW plastic, but can be glued with epoxy. I cut a block and just milled a series of slightly undersized holes for the shells, then cut off the facing to make the slots (which allow the shells to be inserted , but still grip them firmly). I cut a couple of kerfs in the backside of the plastic and just glue it to the M6 with epoxy. If I ever need to remove it I just heat the metal slightly with a heat gun and it pops off.. From this block of plastic I've made about 10 for .410's and about 20 for .22's

. I probably only have enough material left to do 2 more, so if anyone recognizes it tell me what it is so I can find more!
WW