The factory put several different types of seals in the doors along the way.
Univair sells what they claim is an original Cessna doorseal, their PN
S249-2 for .73 cents per foot. It appears to be a hollow quarter-round
type. My own airplane has what looks like their PN 187-610, (which was also used by brand "P",

Univair at http://www.univair.com tel. # 888/433-5433