Hello Peter,
I don't know whether you have one of the following publications:
- Ab A. Jansen, Schiphol (3 volumes)
- R. de Winter, P. Grimm, E. van de Loo, Vliegvelden in oorlogstijd
- G. Matiello, Fliegerhorstkommandanturen und Flugplätze der
deutschen Luftwaffe 1935 - 1945 Einsatzorte und Einsatzzeiten
but I can recommend you to contact Wybe Buising / Houten for Hilversum related questions and as he is also the secretary of the Studiegroep Luchtoorlog (see
www.airwar39-45.nl) so he might be able to help you with other contacts.
All the best, Marcel Hogenhuis / Venlo (co-author Vliegvelden in oorlogstijd)