3100,On my '49 the detent springs go in the top hinges.One on the top of the strap and one on the bottom.If you pull the hinge pin out you can see a small hole in the strap and also a small hole in the bracket.If I remember right you have to pull the pin,install the 2 springs then replace the pin.They're not hard to install but it's kind of a puzzle. Chip
