Opened up the tank via the pump/sender access under the back seat and had a look inside. The dent is well forward of the pump/sender unit, no harm. Inside surface looks well-dimpled but otherwise intact. Got the skid plate back into shape and back on to boot!
Planned to let the frame rail and spring perch take the hit, but was a few inches off. My efforts to free myself only made it worse. The skid plate was ripped right off the crossmember bolts, the rear bend was straightened and a new one created a few inches further up its length.
Hi-lifting off the rear bumper and pushing me off it a few times finally got me clear. Remove the 2 remaining bolts holding the skid plate on and we were back on the trail.
The tanks are like 6 or 7 layers thick as I recall, sure glad Nissan didn't skimp on 'em!
Brent