Screw reel fittings are not actually 'modern' so if modernity is the inspiration, don't bother. If the reel fittings are forever coming loose and letting the reel drop, or threatening to do so, I find it's best to put black PVC tape over them to secure them in place; neat and very effective, if a little odd sounding. If you are determined to replace the reel fitting, you are going to have to rebuild the butt, possibly completely. This takes a little time and some skill. Are you up to it? I used to build rods regularly for myself and others, and although it is perfectly possible, I would be wondering if a new rod might be a better solution.
Alan, February 2010