From my personal experience (I have a 1366×768 display) there is to my knowledge no such mods available. For fullscreen I just used my Radeon APU's video re-scaling capabilities for full screen video. The menu however still had black boxes. If your APU/GPU has video re-scaling, try enabling those settings and see if it makes any difference. Otherwise if the black boxes bother you get the aniversary DLC.
It is important to note that re-scaling videos from most games released up to 2008 may produce a lower quality image. More dramatic re-scales like cutscenes from StarCraft (written in 640×400) had RGB blurring and occasional artifacts, while the Oddworld series has vissible pixelation in the cutscenes. Re-scaling only emulates a lower resolution screen to bypass fullscreen restrictions
The reason behind why full screen video for Full HD devices and beter is not supported in TLC was most likely the result of time and money constraints, as it takes a lot of time and resources to convert a video into a higher resolution format. This would also have meant that the game would have needed an extra CD for cutscenes alone.