Hello Bill
Welcome to the Society.
The 'bible' on liberation overprints is 'Catalogue Libération' by Pierre Mayer. It contains excellent illustrations to aid identification and, where known, the dates of issue and printing numbers. He died some years ago but his book does come up from time to time in auctions.
The decision to overprint stamps to mark the liberation of a town was made locally but as the lines of communication between the Administration des Postes in Paris and the regional offices were often disrupted the correct procedures were not always followed.
Once communications were restored, the P.T.T. conducted an investigation into the conditions in which the operation of overprinting had been authorised and effected as well as the means adopted to put the overprinted stamps on sale to the public. A communication from the P.T.T. dated 22 November 1944 contained a list of issues “which have been overprinted on the instructions of an authority qualified by circumstances and which have been wholly placed over the post office counters of the locality or region concerned.” This means that stamps overprinted by the local philatelic society and sold from a park bench to its members did not qualify! Only 12 out of over 160 towns were deemed by the P.T.T. as having fulfilled the criteria and therefore having produced an authorised and postally valid issue. Three other towns were added subsequently to the original list making a total of 15 authorised issues.
The 15 towns are Aigurande, Bordeaux, Châlons-sur-Marne, Chambéry, Châtellerault, Cherbourg, Décazeville, Loches, Lille, Lyon, Méasnes, Niort, Poitiers, Pons and Tours. These are the essential ones to collect and few demand high prices other than Poitiers Type III. Some of the unauthorised items do make attractive additions to ones collection and have interesting stories associated with their production, However, beware of forgeries which are easily created with modern technology. If you are going to spend big money ensure that it is certified and/or signed. Pierre Mayer signed a lot of his stamps but in old age even he made mistakes.
Some issues, particularly after the demonetisation of Pétain stamps on 1 November 1944, were overprinted and put on sale as souvenir vignettes usually as a means of raising funds for prisoners of war, the Red Cross and other war related charities and were never intended to be postally valid.
