From the 1957/63 Ford Truck Parts Catalog (available on a CD from hipoparts.com):

1957/60 F100/1100:

B7C-8142084-A .. Back Glass Weatherstrip-Use without Wrap Around Glass / Reproduced

B7C-8142084-B .. Back Glass Weatherstrip-Use with Wrap Around Glass / Reproduced

That's it...there isn't another.

If you have a Custom Cab, but it does not have the mouldings...now...it did originally. A previous owner, at some point...likely replaced the back glass, as it had broken, omitted the mouldings.

With mouldings: The weatherstrip has a groove in it. It can be a PITA to install these mouldings, one possible reason why they were omitted.

Or...one or more of the mouldings (there are four) were damaged when the back glass was broken, possibly caused by something in the bed moving forward when a PO came to a stop.

B7C-8142404-B .. Back Glass Moulding-Lower Right / Obsolete

B7C-8142405-B .. Back Glass Moulding-Lower Left / Obsolete

B7C-8142430-B .. Back Glass Moulding-Upper Right / Obsolete

B7C-8142431-B .. Back Glass Moulding-Upper Left / Obsolete

AFAIK, not reproduced. No Ford Dealer or obsolete parts vendor has any.