Vintage Hubley Colt 45 Western Cap Gun

1950's Hubley die cast western Colt 45 cap gun. Takes 2 piece shells for round caps. Shells missing. Near mint condition. Needs minor repair. Hammer works and mechanism works which turns the cylinder. Cylinder slides forward out of position when fired and does not turn. I believe the wide metal tension spring which pushes against the bottom of cylinder is weak and not holding the cylinder back in position. Metal spring is pictured.