Look for pics of just a head. They will look like the flange in the lower pic with about 3/4 in of pipe sticking out and same screws.
They are used from 69 -76 on K bikes
Your pipes come off so fast with that setup, some take them off to change oil(not needed with Hooker and most) or clean the bike/pipes.
We used to change the finned clamps to flat ones, they open and close easier and are clener looking (IMO)