The inboard slipper sheared off at the fastening bolt, slid down and had two grooves worn into it from the lh bank chain.
Chunks are surely in the oil sump.
Putting it all back together tomorrow.

I used the CPS hole with the crank licking tool. I used two cam locking bars. Replaced all four chains, tensioners, and primary guide rails.
After torquing everything correctly, I removed bars and CPS locking peg. I turned the crank over with a socket, two revolutions, which brings me back to where I started.
I wanted to see how everything behaved. With the RH cam flats aligned, the LH cam flats are trailing. Is this normal? Will it correct itself with oil pressure on the tensioners? Or have I made an error in the installation process?
Waiting patiently for replies from the group. I'm not fitting the timing cover until I get it right.
Thanks for a great forum.
1998 xk8 4.0 NA.

I went back and inserted the CPS lock tool. Rechecked Lh and RH cam flats. RH was perfect. Lh- loosely fit bar, loosened both sprockets and retorqued. I had to turn the cam a few degrees with a channel locking pliers, and snugged down the bar. Somehow, must likely due to My less than perfect eyesight, the lock bar was down but cam flats not perfectly aligned.
Removed CPS lock and cam bars. Rotated several full cycles. Nearly perfect.

ITiming tool kitStretched and broken think the tool stretch while torquing the sprockets led to the cam flats being out of line. Time for a different tool.