I can add copper-plated cuirasses (and gold plated ones for the officers). My source, apparently the same as Harper's, is Arthur Chuquet's history of the unit ("La Legion Germanique 1792-3", Paris 1904 but available online via Google Books if you're ok with the French).
The main problem with all this is that the uniforms mentioned are not taken from in-service descriptions, but a "Capitulation" from the legion's first commander Dambach - essentially a pitch to Robespierre to let him go ahead to form the unit. The Cuirassiers Legers were one of his pet theories, along with the Regimental Anthem...
The Legion was certainly formed with units called "Curassiers", "Piconniers" and "Arquebusiers" etc. But given the state of France in 1793 it is highly unlikely that much of the planned uniform and exotic items of military equipment to go with those names were ever issued or carried into action during the Legion's brief (and less than effective) military career. On the other hand some attempt was apparently made to buy lances for the Piconniers, although no-one seems to have thought of targeting recruits who knew how to use them!
All the best,
Peter