I wonder if it can be fooled like the old w95 upgrades.  There were a
few known ways to do it but this one might work???  Easy to try anyway.

Create a Notepad file and type in some random characters, it don't
matter, save it as win386.exe .  Put this file in the root folder of
your formated drive (save it on a diskette and when in DOS copy it to
C:\)  Now try updating.  No saying it's gonna work but no harm trying.
Let us know if it works, I'm curious...

John