The writers missed a great opportunity... they should have had the elusive Mrs. Columbo materialize in one of the last episodes or movies. Not as some cheesy spin-off character (Kate Mulgrew), but as a special guest star, the bombshell Italian wife nobody would expect, played by Sophia Loren.
This is like the opposite of bringing down any argument by introducing Hitler into the mix - what show ISN’T improved with the addition of Sophia Loren???
The real mystery is how does he keep that Peugeot 403 functioning.
(aculeus is a Peugeot survivor.)