re: Old Codger Safety

Get you a sheet of Kaizan foam Ron.  Cut it the right size, heat the end of the offender a little with a torch and press the foam onto it.  It'll be a perfect fit that you can take on/off as needed.  Depending on the shape, you may not even need to heat it.  3D printing will certainly work but requires the time to measure and layout the design - simple for some things, not so much for others.