Doors and windows 12,000.
Roof? But £25k if required (You wouldn't want to do this if planning loft conversion in future)
Modest kitchen and bathroom £28,000.
Fitted cupboards (set of wardrobes and sitting room cabinets £3500)
Total redecoration, plastering where necessary £10,000.
There will be some damp in a house like this - allow £6,000 subject to full damp and wood survey.
Internal doors? £2500
So without loft and side return I'd say £65,000 minimum. With loft and ext and roof possibly just about £150,000 but it will be tight. Will the return be worthwhile?