What you say is true.
But those who engaged did so for a variety of reasons
- The fight
But also to get a new identity because
- They had committed a crime (theft, ...)
- They wanted to disappear in the eyes of their family, a pregnant friend ...
Legion is a very closed place and it is difficult to obtain information.
You give no indication,
- neither the names and surnames, (official ones or those under which it appeared),
- neither his date nor his place of birth,
- nor his military number
Without anything, I can't try
You can try sending a mail to
Monsieur le Général commandant la Légion étrangère
Bureau des Anciens de la Légion étrangère
BP 21 355
13 784 Aubagne cedex
Remember that you talk with a General (even if it is not really him who will read and answer the mail), not an old chap!!
And tell him EVRYTHING you already know and give evidence of your filiation with him. If you procrastinate, you will not get anything. If they begin asking you some questions, you will not get anything.
Do not miss anything
It is not a public service, they answer if they want it and have no justification to provide to anyone.
It will be hard, but if you are a grandson of Legionnaire... ;-)
If you have no answer, you can try this ( aviaible for all military not specificaly Legion étrangère) "Service Historique de la Defense - Centre des Archives du Personnel Militaire"
64023 Pau cedex