I got a sling made for a lever gun (it was all i could find and i needed it in a hurry) Its the barrel band type but mine only the half band made to fit on the mag tube of a lever gun but it fits my barrel so... Uncle Mikes actually has 7600 swivels...

This ones for 1969 and older
http://www.unclemikes.com/products/remington_760_7600_68older.html

this is for '69 and newer...
http://www.unclemikes.com/products/remington_760_7600_69on.html