For the very first level;
The first node's coordinates are 288, 800. That's 18, 50 in tile coordinates (I searched for both without luck).
Node to the left of the exit is at 47, 5 (752, 80)
Node to the right of the exit is at 60, 5 (960, 80)
Player start should be at 128, 1216 (8, 76), but I'm not 100% sure about this.
In memory during run-time they are stored as unsigned shorts. I tried looking in levsdat.bin too, but didn't find anything. I'm still trying to figure out what exactly is stored in it.