Hi
Justo saw your 10 year old post
I am a uniform consultant for the Portuguese Military Museum
In my opinion your shako is not authentic, for several reasons
The Portuguese 1806 pattern shako had the plume on the side, not on the front. Caçadores (light infantry) units, which were raised later, dit not wear that bugle (they wore a simpler one). They also did not wear the number lower plate (that was worn by infantry regiments). The national colours are nothing like the originals. Finally, Portuguese shakos for foot troops never display metal edges on the peaks. That was strictly reserved for mounted units.
I am sorry
Regards
Pedro Soares Branco