The hammers, sears and cocking dogs appear to be in proper relationship in the pic. I'm not sure you could get these parts in properly if the mainsprings were wrong. On some guns,the forends are difficult to fasten if the hammers are not cocked. You could try to manually cock the hammers by pushing on the cocking dogs where they lay under the hammers. A narrow bit of wood and the frame placed on a firm bench or table should make the job easy. The wood is so you don't mar the metal parts. The cocking starts off hard but is easier once you get the parts moving.
