Gravity Well - Harry Nelson by Bits & Pieces

I gleaned this info from ‘Age of Puzzles’ by Serhiy Grabarchuk:

“Harry Lewis Nelson is a mathematician, computer programmer and expert, math editor, and devoted puzzle inventor. Nelson earned his degrees in mathematics from Harvard (1953) and the University of Kansas (1957). For 30 years, since 1960 until 1991, he worked with supercomputers at the Lawrence Radiation Laboratory / Lawrence Livermore National Laboratory (LLNL) in Livermore, California.”

This is one of many puzzles designed by Harry, here’s a brief description of Gravity Well:

“It is a nice (though difficult) take-apart puzzle. Your goal is to disassemble the whole shape into three rings and a core, and then to reassemble the shape.”

The information sheet that accompanies this puzzle shows three different challenges for this cool puzzle.