Does anyone know where to get the rubber gasket that’s at the base of the roof visor, mine is turning hard and starting to split ?
I doubt you’ll find that anymore. Your best bet would be to just buy a new visor 
I have my doubts also, but seen newer cars with them on, so somewhere there has to be a supplier for the new ones ?
AVS (Auto Vent Shade) has the visors
Dug around a little, looks like Weather Tech by Mac Neil makes a roof visor similar to ours, i’ll phone tomorrow about a gasket.