You would usually need a different BB axle if moving to italian cups, but sometimes you can get away with it, of the english thread cups are thin wall and the italian ones are thick wall, and you have enough threads to play around with on the NDS... biggest issue is likely to be chainring to chainstay clearance though. With cup and cone BBs sometimes trying different combinations will work out OK but not always. What chainset is it, and what BB length does it need?
I have no idea on the age of the Raleigh, could be that the bolts were just tightened down to much, or maybe installed without any grease so have seized, or maybe even just down to having never been removed in a very long time (or a combination of any and all of the above)