For archaeology, there are various sectors of the broader discipline which already have access to most if not all of the complete range of maps from the OS. Those in higher education (at subscribing institutions) can access the Edina Digimap service which offers everything including historic maps ,all scales of modern maps and other geographic datasets. Local authorities generally have access to various maps often now including mastermap but often the historic maps too. Similarly, English Heritage and I imagine other similar bodies have a complete set of OS data. I appreciate the licensing arrangements are restrictive in terms of reuse and provision of data to third parties, but it is certainly possible in certain circumstances; perhaps what is needed is more cooperation and flexibility with licensing…? Or the government to find a way of increasing funding to the necessary bodies to compensate for the loss in revenue so the maps can be free to all; they’ve managed it in the United States after all, where geographic information is free to all.