Alright guys,
The possible load of this gun was a false alarm
.
I have just taken off the paper plug ... and nothing else was there.
I blew it and the air goes through.
The paper is part of some kind of receipt, issued by an old Portuguese bank, back in 1953.
So fine i won't have any troubles extracting the load from the barrel.
... and the little paper becomes collectable, attached to this blunderbuss.
In this case the gun may not be Portuguese, but has been around for a while
.
Fernando.