Duneau, Historique du 48e régiment d'infanterie, 1610-1878

Might be available from the BNF in microform:

https://achatsreproduction.bnf.fr/views/vel/mon_panier.jsf?provenance=Catalogue&urlReferer=/ark:/12148/cb303772922&AppOrigine=Catalogue

Apologies. Only the Notice bibliographique may be downloaded, not the actual book.

Thanks for the tip! Unfortunately I am not able to find a download, but maybe I am looking at the wrong place. P.S. I am mainly interested in the 1799 period.

The Bibliothèque nationale website has a copy which may be downloaded