Hey, Lee. I have my 2 barrel set gracing the walls in my garage too.
To continue the mystery of these covers, I found another set,while surfing E-Bay, and they have the "2 stove pipes" AND the large bracket. I thought the "2 stove-pipe" models had just the small brackets...sheesh,this is gettin' complicated!
PS...Lee,are those Ch*vy hold down clips I see under those valve cover bolts????....Tsk..Tsk...Tsk!!!
Check'em out...