Need special bolt for jump seat for 66 burb

[1966burb]

I know this is a long shot, but throwing it out. I need one special bolt for the pivot or hinge point on my passenger folding jump seat on my 66 burb. The part that is special is the shoulder under the head of the bolt. I have searched shouldered bolts and have found nothing close. I may have just make a sleeve that slides on the bolt but OD dimension is odd so it will need to be turned down on a lathe. Hoping someone has a rusted out or broken frame in their special junk that has the bolt I need.