I am not sure that anyone using the forum collects the French Tresor et Postes datestamps from WW1, but I thought I would give this a try.

I attach a picture of a cover 9-8-19 cancelled TEP *520  * (space between the 520 & *). Bertrand Sinais is the reference for these marks, he records three variations to TEP 520, he does not show this configuration. His records show later use of TEP 520 in Szegedin Hungary (French Serbian occupation), which would fit with this date.

Does anyone else have any further information?

Thank you