My gut feeling is that a 113mm BB spindle is too short for a Raleigh GP to give the correct chainline. The GP has a pretty large offset on the chain ring side. As I mentioned, I used 122 and 127 mm Shimano BBs with Suntour cranks. So, I think you are faced with the following possibilities:
- Trial and Error- If you want to use the current BB, you will just have to experiment. Pick a crankset and see what kind of chainline you get. See if it is close to where it needs to be. If it's close then based on whether you need a larger or smaller chainline, you can make a choice of ISO vs. JIS, or the various manufacturers. Sutherlands has a diagram that shows in a relative way where the various cranks line up on the tapered axle. But it won't vary by much. If not so close you will need a different size spindle. My suspicion is this BB is too short, but you won't know till you actually try it.
- Known combination- Scrap the BB and use a BB and crankset known to work or known to be close.
- Retro fit- Scrap the cotterless BB and go back to the Raleigh cottered cup/spindle/crankset. They are cheap, easy to find (I've got several lying around). On the downside, they are heavy and they have cotters. This is your low cost solution.