Seeing the most recent discussion direction I thought I'd show a few pictures of the masking (!)
The final chassis black has now been applied to the underside and after a bit of playing tomorrow with a new paint product (I can't wait - so exciting) I'll be tipping the car back upright.
The chassis black will be dry enough tomorrow to allow some masking of the holes in the floor pan (holes that are meant to be there - such as drain holes!). The underside will then be covered / masked before I flip it back upright to protect it whilst I carry on with the epoxy and painting of the inside of the car.
Oh yeah - forgot to say - Dauboline - didn't try it after all - after cleaning out the transmission tunnel are I just went for Eastwood rust encapsulator...