removing tomettes or not?

[Lassie]

We are thinking of buying a stone house about 150 years old.  Its in basically good condition, walls and roof, but needs rewiring, replumbing and updating the central heating.  Its not been lived in for many months and there is a lot of leaf litter and dead vegetation around the building with overhanging trees. The gutters are full of moss and some downpipes are out of line. This is contributing to a potential damp problem but is easily sorted out.  However, a builder came round to look ( a Brit) and said we should take out the tomettes on the ground floor , dig out out , lay a membrane, pour in concrete and put down carrelage or wood. He had fun with his damp meter finding new bad areas on the floor and walls as you would expect in an old property which has been shut up for months.  Having had a similar property before, we lived quite happily with the tomettes and assume they too were laid on earth a long time ago.  However. the area around the cottage was cleared and gravelled. With permanent occupation, central heating and good ventilation there was no particular problem.  The quote will be high and we are really wondering if its strictly necessary or that he is just short of work at the moment. Any experiences to share on this please?