I had a call once on what it would take to do a magnetometer survey over the Everglades to look for a 55 gallon drum. Seems these guys had a lead that Jimmy had been chopped into pieces, put in a drum, and then dropped out of a plane!
I told them “good luck!” (Impossible project, and “treasure hunters” never pay.)
And it sounds too elaborate to have been a real plan. The old classics work the best. In a century or so, when the name "Jimmy Hoffa" means nothing, the Ren Cen will probably be demolished, and they'll have to sort out which of the mob-buried remains are his.