Just been looking in the Yellow phone book for Ipswich and yes, Cragpit Farm, Tattingstone still exists but the address is now The New House, Cragpit Farm, Tattingstone so I am thinking that this was constructed in the 1970/80 when the reservoir was built, the cottages may have been nearby to the farm. A new road was a built to bypass Tattingstone and the reservoir, the A137, and Lemon's Hill Bridge was constructed to link the north and south parts of the village of Tattingstone after the valley was flooded to form the reservoir.
Terry