Sounds like you've got an early HG front idler on there. Late HGs, OC3s, and OC4s use idlers that have two rims that ride the outside of the track chain (no center raised rib).
As to cutting off one side of the track pads? I had to do mine on my 1010 and it's been fine. 14" pads from a Deere 1010 dozer were too wide for my Deere 1010 loader. So I had to cut off one inch on the inside.