Have Iona shoe polishers desirability been supplanted by the Spirit and other PKE meters widely available and inexpensive now?
It can’t be denied that the Mattel P.K.E. replica did provide a convenient option for Ghostheads that saved them a lot of hassle in converting the Iona and sourcing a P.K.E. electronics kit (which weren’t very common compared to other light kits out there). The Spirit P.K.E.s probably do provide a convenient pre-built option, though not as good as the Mattel predecessor.
I think there has been a bit of renewed interest in people making P.K.E. replicas from scratch, but in a limited capacity.
And then there’s the fact that Iona polishers are getting rarer with each passing year.
On top of what Kingpin said, there’s also the 3D printing space. I’ve seen several printable models of a movie accurate PKE and a couple designed specifically to house the Spirit PKE electronics.
I have one that I bought years ago. It’s in one of my bins o stuff that I need to sort through. I’m not up to refurbishing it into a meter anymore so once I find it I’ll either sell it or trade it