Thanks alot for the help. It turns out that flipping the TIFF file is not necessarily the problem I'm hitting here. In fact, I found this piece of text:

Programmers working with bitmap files need to be concerned about byte order, because many popular formats such as Macintosh Paint (MacPaint), Interchange File Format (IFF or AmigaPaint), and SunRaster image files are always read and written in big-endian byte order. The TIFF file format is unique, however, in that any TIFF file can be written in either format, and any TIFF reader must be able to read either byte order correctly regardless of the system on which the code is executing.

So, I'm going to pushback on the user. This is being generated from a very very very old piece of Windoze 3.1 software. I suspect it's generating dubious files. In fact, stuff like the GIMP, ImageMagick, etc can't properly identify the file.

Thanks for all your help.