Hello Tunneller
Your questions are quite understandable and would probably require lengthy answers.
Nevertheless, to put it in a nutshell, this is what can be said of French awards such as the group you show.
1. As a general rule, the badges and insignia of French awards bought by the recipients (or presented by military units or by friends). They can be freely bought from a number of sources, including the Paris Mint at a reasonnable cost.
Undue public wear of awards is quite severely punished by law.
2. Most official awards are gazetted in some way or another. Legion of honor, National order of merit and médaille militaire are gazetted in the "Journal officiel de la République française".
3. Awarding authorities deliver a brevet or certificat, allowing formal ware of the insignia. The three awards mentionned in §2 have to be formally given.
4. After WW1, a number of well produced and illustrated "certificates" were made available commercially in order to allow the display you show. They are period and quite legitimate, but they must be understood as private initiative.
I would say all the medals of that group were bought by his family. There may have been insignia sent by the regiment or other sources, but this would not change the symbolic value of the group.
Hope this answers some of your queries. Please feel free to ask further information as you wiish.
Chreers
Vetéran