Shelby Seatpost Bolt?

[SKPC]

Is this a Shelby-specific seat-post bolt? What other bike or bikes had an "S" on the seat bolt? It came on my 37 straight-bar..

 

[ZE52414]

Didn’t Schwinn middleweights use S seat post boots?

 

[rhenning]

Lots of Schwinns used S bolts for years. Roger

 

[SKPC]

Thank you gents....it must be a Schwinn bolt. Did Shelby use generic binder bolts on 30's frames?