There are yet errors to correct in the general philatelic books. Introductions of catalogues about French oversea possession of La Réunion will have to be amended because of what Benoît Chandanson found in the Departmental Archives of the island.
Dealer and author specialised in La Réunion, Chandanson just published a letter that would permit [conditional: let's critics study the new document and thesis] to precise the numbers of the first Reunion stamps that were issued for local purposes in 1852 and served until 1860. On 16 February 1852, the local director of the posts write to his colleague Director of the Interior about the incoming order of the new stamps. While catalogues Yvert and Dallay (2006-2007, page 293) has been giving a 7500 stamp printing, Chandanson's estimate by this letter is lesser and better sourced.
The document reference: 6P123, Archives départementales de La Réunion. The 6P indicates the topical ordering of the archives, here the pre-1946 départementalisation documents about "Finances. Cadastre. Posts. Credit companies."
The article: Benoît Chandanson, "Réunion 1 et 2: chiffres de tirage(s)?", ColFra #394, October 2008. ColFra is a French association specialised on all philatelic, postal, marcophil, etc. topics in the former French colonial empire.
* go search the nearest local archives and see what could be about posts in there. In France, departmental archives kept the prefect's archives and some of the cities' archives (example of subjects you may find in those documents). Your local archives may have such documents as debates and petition about the building or establishment of a new post office, etc. ;
* even if some do not find them pretty, even a little bit invasive, to multiply intra reference notes let the reader know how important affirmations were assumed and which one are lacking strong proofs.