You can get the latest version from Andreas Beck's page. Kai Nacke is the new maintainer.
As far as I can tell, the changes from 0.0.4 to 0.0.5 are the same as my patch below with the additional corrections to remove the compiler warnings that I ignored when compiling 0.0.4. If you already installed scanner.h and scanio.h in a global include directory, you need not replace with the 0.0.5 versions, as my patched versions are identical.
The latest driver for the Logitech scanman hand held scanners that I could find is version 0.0.4. And I found it needs a patch to work on my RedHat 4 (2.0.18-6 kernel) system. You mileage, of course, may vary.
patch < logiscan-0.0.4.patch' to patch two of the files in the src directory.
You will get some warnings during compiling, I ignored them and it still seemed to work.
I found that this driver module works fine with Pbmscan 1.2 without recompiling. Although I got a much smaller executable when I did recompile.
Thanks to firstname.lastname@example.org (Gerhard Siegesmund) for putting me on the track of this driver. I used the great Linux Archive Search page to find it after Gerhard gave me a name to go on.
The original location of the driver is here.