Check McMaster Carr.com under the screw and bolt sections. Look for a shoulder bolt that has the diameter and length that you need. Also use a nylon insert locking nut. The locking nut will able you to leave a tiny amount of play to keep the joint from binding. I did this fix on my top and it works great.
They also sell brass bushings. You may modify the bushing o.d. and i.d. slightly to fit.
They also sell brass bushings. You may modify the bushing o.d. and i.d. slightly to fit.