If anyone cares the '06 shock doesn't have high-speed compression damping adjustment.
Seems to fit fine. Looked like the reservoir would go into the cutout I made for the 07 shock, but I didn't verify by mounting it without the spring and compressing the suspension.
The way I tried it to start out with, it's much better than stock, but not as plush as the 07 shock with rebound and low-speed compression set fairly high, and high speed compression set low. Maybe I can lower the compression damping setting a little and get a good, controlled ride.