what to do about my vent windows?

[Daves72'GMC]

I'm 3/4 through my frame up restoration and was getting ready to clean my vent windows and noticed the vent window rubbers are cracked on both of them.Has anyone bought new vent windows and how is the quality compared to the origionals? My vent windows are in perfect shape and I know they make a rivet and seal kit, but don't know how to put them in. and I've heard they almost always leak and make noise if you put in new seals with the kit.Is it just easier to buy new vent windows and is there anything negative about the new ones? Thank you all, Dave