Grey Black Floor Pan Colour

Does someone know the actual colour of the floor pans VW did for the '68 Beetle? Is it the Standard Grey Black that VW quote for their body colour or was is just some leftover paint mixture.

It is quite a dark grey whatever it is. Part way between full gloss and satin/semigloss. Does anyone know where one might get it mixed with the correct sheen?

I'm about to paint my pan with KBS or POR15 and then try and overcoat with the period correct grey black, but I need the overcoat so I can paint just after the rust paint has been applied.

Also, I don't have a proper body spray gun, only a cheap $20 one. I do however have a good solvent capable airless. Any idea if these will give a reasonable finish for what is really a hidden area? I don't want to experiment on expensive paint if it is a complete dud.