Bruce,

1947-1955 panel body cab to running board seal (for 1/2 ton - 1-ton would be longer - I assume such a seal was also used on a 1-ton?). Whatever seal was used on a Chevrolet would also have been used on a 1-ton.

I do not know of specific "rocker panel" parts for panel-body trucks (unless Ray Stanley makes them); however, people have reported that the bottom outer door skin-panel can be used on panel-body trucks' rear-body "rocker panel".