Here's the fix:
1. Open config.dat in a hex editor such as Breakpoint Software's Hex Workshop. You can download older versions of Hex Workshop for free on the Breakpoint Software website. I'm using 3.11 under Windows 7 64-bit and it works fine.
2. The 4th byte from the beginning of the file is the horizontal resolution. It's a signed/unsigned 32-bit integer, 4-byte data. If you look in the lower left corner of the Hex Workshop screen you'll see it translated to whatever resolution you've set, 640, 1024, whatever.
3. The 8th byte from the start of the file is the vertical resolution. It's also a signed/unsigned 32-bit integer, 4-byte data. Again, if you look in the lower left corner of the Hex Workshop screen you'll see it translated to whatever resolution you've set, 480, 768, whatever.
4. Simply change the values to whatever resolution you want and save the file, the game engine will do the rest. Scaling with this fix is perfect, no long, flat, sausage-shaped choppers or anything. Here's a screenshot from SAR4 at 1920 x 1080 on my computer. I believe this should work for all the Search and Rescue-based games.
I'm running the game under Windows 7 64-bit and it runs just fine. With the widescreen issue fixed, it's a nice bargain title for helicopter fans.
Hope this helps some people!