I think Retro Resurrection looks similar.
Though it is not assymetric.
Sledge could have multiple different looks from very flippy to very smooth because of mass bias core.
Could also act like pearl or Solid.
I love the new Morich balls (Mo designed Sledge core) but they seem more angular than the Sledge.
Sledge always started with a rounded move and then it either flipped(mass bias strong) or rolled (hook set drilling).
There are still some used ones in good shape to be found.
I have two! Could have had more!
REgards,
Luckylefty