I have a relative who has been spending years collecting data from archives and building historical maps of Ostrava, a city in Czech republic [1]. He built nine

I have a relative who has been spending years collecting data from archives and building historical maps of Ostrava, a city in Czech republic [1]. He built nine (9) time based layers (1860-1940). The amount of time and work this takes is just incredible. He has been considering providing data to OHM, but obviously has not been convinced by this prospect yet, one of the reasons has been loss of control over his data, as there are academic institutions ready to snap this a put their name on it. It was already attempted. I can imagine there are more researchers like this and the results of their work, all the data, is fragmented somewhere out there... and possibly lost. 1: http://www.mapomol.cz http://www.mapomol.cz