Correct Outrider...the M85 bags did have a canvas pouch that buttoned in,
the M59 did not and were quite a bit smaller.
The M59 consisted of the pocket back with a expansion welt & the front , sewn to this front and into the welt was a second
pocket about 1 " shorter at the top. This pocket was laced partially to close.
Sewn to the back was the closure flap with is single strap/buckle safe & sandwiched between was the cantle saddle strap
This strap was slotted on both sides to fit over the McClellan saddle bag staples and a billet then passed through the stapel to tie the bags in place , there was also a vertical button brass post at the center of the cantle this fit a single punched hole in the Bags cantle strap.
There was also an M74 pattern