Without any spare cash we decided we would remove said carpet and, if everything was ok underneath, we would sand and stain the boards as an interim measure.
What joy as we discovered a set of pretty decent floorboards underneath, most still untouched by bodgers and with original tongue and groove joints. However as I worked my way across the room, our joy became short lived as I discovered the boards came to a sudden end. Unfortunately, one third of the floor is concrete - and not even nice concrete at that as patches of the previous tiled floor show through in places.
So we will have to live with this for a bit and try and paint over this area to blend in as best as possible. Got any spare green carpet anyone?