Found the MagPul sling mount I wanted but was more expensive on the usual sites....
MAGPUL PTS RSA Rail Sling Attachment Point MS2 MS3
ebay for $17.95 with free shipping... sale ends in 7 days
MAGPUL PTS RSA Rail Sling Attachment Point MS2 MS3 Black Rifle Tactical USA | eBay
sorry don't yet know how to post images