One can't prove a negative (as in "A Jagdpanther in allied markings did not exist".) However, knowing the uniqueness of such a vehicle, if any previuosly known photos existed, this rarity would be very obviously familiar with those interested in WW2 German AFVs.
I think you need to go to another AFV if you're looking for photographic evidence (which is what I'd advise you to do as well).
How about late war Panthers, Tiger Is or Pz IVs used by Free French forces that were part of the blockading forces the stay-behind German "fortresses" in ports along the Atlantic coast like La Rochelle and Saint-Nazaire? Those are very interesting!