Did not achieve much today. Am currently considering how to establish a flat floor at the entrance, given that the metal work is on two slightly differing levels.  I cut a plywood template for the shape of the floor and intended to use this on top of the tongue-and-groove but this looks as though it won’t work.  I think there must have been a steel plate or strip infill on top of the angle iron to make it all level.

Whilst pondering this, I primed the exposed woodwork in the entrance floor area then cut a small section of floor board to fill in to the left of the step well.