New year plastering and fireplaces renewal

Logicearl

We have a mid sized Victorian 3 bed terrace that has, over the years, had various updates done to it. One update was to convert the two downstairs living rooms into one. This room now needs work doing to it.
At some point in the past the bottom 3 to 4 ft of plaster has been renewed (damp proof) all round. The rest of the plastering seems shot, so would need re plastering. The walls in question are somewhere in the region of 12ft high and the two rooms approx 14ft square each. The ceilings look as if they have been renewed too, so a skim should be all they need.

As for the fireplaces, they need to be reopened, someone has used odd shaped stone blocks that cover the whole width of each fireplace, to just above the gas fires, that sit in front of each chimney breast.

What sort of cost are we looking at for either/both jobs?