Thanks to nickybaruch I am now considering doing the floor (which is now sanded back ready for finishing off) with white liming with a slight tint colour in it. Some say you have to be very careful when liming. Is this a problem? I would have thought it would be just like putting on a stain? Anyway doing it that way we would still see the grain of the timber floor which would be lighter than the dark cedar it was before and keeping the pine lined ceiling with the cedar coloured beams will blend in well I think with the lighter timber floor and the white walls we now have. What do you think?

photo please? that way we can have a look?

may be a good idea to finish timber to protect from drying and cracking..check with specialist paint suppliers but we used to use a mix of linseed oil and terabine (drying agent) that was very successful to protect old timber without changing the colour too much

I would prefer to see both ceilings matched with shiplap, to help tie the space, we all tend to look up. This would also mean that the wall between both rooms can be removed and therefore make the room appear bigger, as the height of the ceilings in each room will make them appear smaller if the wall isn't removed