Fernando K is most certainly right. I didn't care for the missing hole of the pan & frizzen and only looked to the 'poor quality' of the percussion hammer.
Yes, it would be interesting to know whether the ignition plug is welded to barrel or screwed instead ... a sign of later addition for a conversion, right Fernando ?
In this case this trabuco would be of a more recent production, same as the percussion system was popularized ... around 1830
