Drip rail seal kit?

The filling in the drip rail was cracked a few places at the front bottom of my 1965 Dart. I picked out the loose section (~2" each side). The rest was solid and well bonded, plus showed no surface rust, so I left it. After wire-brushing rust and primer, I filled the missing sections w/ PL1 white polyurethane caulk which I had from my trailer repair. I think it is better quality than silicone and matched perfectly.