OK! Here's a save for the multipatched game that leads to ALT within 5 seconds:http://www.mediafire.com/?2k99w3tjabvj1ak
And here's what the screen looks like as you go to binoculars (for some reason, the back wall of the alcove is invisible):
The dark triangle along the left edge is the left corner of the alcove. This looks a bit different, in-game the dark edge of the triangle points right at the lower-left corner of the image. But it doesn't have to be exact. In my video of the ALT she's turned a couple of degrees to the right.
Anyway, embed Lara so she's all the way to the corner, turn so she's like the screenshot, and use binocs. Wait a second, hit the space bar, wait another second and hit Roll, and within 5 seconds you should see the FMV for the next level. I always see some thin white lines for an instant, followed by crickets chirping, followed by a close view of Lara's head in the FMV. It may not work this quickly every time, try it again. It was mostly 5 seconds for me, but once it was 20 seconds.
BTW, I loaded Jeff Reid's multipatched saves from Stella's site, and started from a Pharos, Temple of Isis save so I could enter Cleo's Palaces with the usual jump-by bug.