Hi beroe
I second Rene66's opinion, especially as he already pointed out that you could translate your existing data into a known format like fbx or dae outside of Cheetah. If you're used to such tasks, you have the tools, the skills and the only thing would be to get the knowledge about the new format. This solution would have the advantage that you could use the resulting file in (almost) any 3d app, not only Cheetah. And you could do it anytime again.
It would be time consuming, though. So even with 1550 keys (the 'time points') it really could be that you're faster doing it by hand instead. It sounds horrible, is tedious and like you I'd do almost anything to avoid such work (even if it would take slightly longer, only for the advantage of being not that boring). If it's only remotely possible that such a need will arise again in the future, I certainly would go for doing the script.
Nobody here around has something ready that you could use (even if somebody had such a script, you still would have to change it to your needs). So, you have to do it yourself from scratch, be that keying manually or scripting.
But what I ask myself, is simply where you get your data from. Isn't it possible to export the data into some other file format – not necessarily one Cheetah can read, but something that could be 'translated' in another app? Or it could simply be possible that someone else using that app had the same problem and has a solution? So you could ask in their forum or simply ask the developers. What app doesn't have such export functions? Or is it so darn old that formats with camera data are not supported?