Detroit Precancel With Initial Only (No Date)

Not sure what this might be. Looks as if it was intended to be a dated precancel but only the initials "DI" got affixed to the stamp (no date).



Could this be intentional, since it was below the denomination for which dates were required? If so, why bother to imprint the initials...could it have simply been intended as a security measure? Or is there another explanation?

Anyone know what company "DI" would have represented?

Thanks for any info.

Got that catalogue at home, will look up when I get there!

The overprint "D.I." is not listed in The Handstamp Dated Control Handbook.
The closest would be "D.L.I." for Difco Laboratories, Inc.
It is possible that this could be an unknown alternate for Difco.
It could also be another company.
It may also be philatelic in nature where a collector/dealer created it by using their initials.

Thanks for checking. Actually, I found three of these amongst an accumulation of 5 cent Roosevelts and thought they looked a bit different with the "DI" initials.

Incidentally, if I web search "DI Detroit, Michigan" I come up with Detroit Institute of Arts and it would almost make sense that they could have been the user of a precancel during that time period, although I would think "DIA" would have been a more appropriate set of initials for them.

Anyway, thanks for trying.