Getting the proper rivets is worth it: too long, and they go all the way thru and leave a jagged, finger-slashing protrusion underneath. ? While the trim's off is the time to check the integrity of the seam, and you can use MarineTex to fill in old rivet holes. Resist the urge to just glue the trim on with silicone.
The metal trim is expensive bought new and is expensive to ship, new OR old, so treat what you have with care.
There is a slit-tubing kind of vinyl plastic bumper type material some people have used instead; if you're not a purist, it can work, and a coil of it ships easier than a 10-foot-long stick of aluminum, though the price may not be any better. ?I've even seen people use white garden hose and thick rope as replacement edge trim, but I don't recommend those except in the most desperate cases.
