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Perhaps not a "source", and not 1814, but here are some painted metal scans with mounted french infantry officers with pre-Bardin lapels.
http://dare.paradise.net.nz/valeur/infantry.htm
I have a book with Edouard Detaille's paintings, and it does have a black and white picture of a mounted french line infantry officer in Bardin uniform. Counted find it on the web and don't have a scanner, unfortunately.
I checked it an cannot find any mounted infantry officer in the Bardin uniform, neither in the Freiberger, nor in the "Camp de Dresde", on what page did you find them??
on page 117 of the Campe de Dresden you can see the
details of officer shabrackes.
Well, they are all ADC's, but Courcelle took this information for line officers too.
so there is no mounted infantry officers in the Bardin uniform in the whole book, I did fear I missed something, as for the shabraques, I still would be dubious if that was used as general distinction, but I did not research that topic.