yeah, i was going to suggest maybe trying to make the dinosaur scenes look jerky like stop motion - that might be a lot of work - might be a simple as dropping video frames.
A Ray Harryhausen sort of look...maybe trim out a few shots of humans and dinosaurs in shots together - give it a bit of an awkward sort of feel like king kong.
the 'missing reel' idea seems like a bit of a cheap gag - it was funny in planet terror but i dunno if it'd work here...
maybe you could incorporate a few bits from JP2 and order it a bit more like the original Chrichton story?
On the whole I like the idea - you just have to be careful not to 'beat peaople over the head' with certain things - for example, I saw a Grindhouse style edit of Mortal Kombat [can't remember who did it] and it was quite well done but they'd used a loop of the same white scratch effect for pretty much the whole film and it became very distracting.
- i do deninitely like the idea of more film distress as something violent is about to happen - that was a technique that worked quite wel on planet terror.