Package and mounting for the bench
The 1.5KE56-B: Housed in a DO-201AA (DO-27) axial-lead package, it mounts through-hole — hand-solderable with a standard iron, no hot-air or reflow profile needed. The bulk packaging means it ships loose in a bag or tube, not taped and reeled — fine for prototype runs or repair stock, but for high-volume pick-and-place you will want the tape-and-reel variant.
Sourcing an obsolete TVS diode
The 1.5KE series is a broad family, so a parametric match (same 1500W rating, same 47.8V standoff, same DO-201 package) from the same series may serve as a functional drop-in — but without an official cross-reference, verify the clamping voltage and breakdown tolerance against your circuit's surge requirement before committing the BOM.