Got this old Spanish copy that was missing the mainspring. Found a repo mainspring from Dixie Gun Works for it but it will require a bit of fitting to work. Has anyone here have any experience doing this. some expert advise would be appreciated. The top of the barrel has TROCAOLA ARAMZABAL Y Cia EIBAR on it and looks to be chambered for the 8mm lebel revolver round. Also does anyone know where to find a schematic of these revolvers?

TROCAOLA ARAMZABAL Y Cia EIBAR REVOLVER.jpg