Ok , the nut was over tightened causing cam chain sprocket to crack/shatter. Drive pin for counter balancer shifted hit the balancer. Causing the eruption of cases,parts & oil. To me and only going by these photos the rest of the carnage was caused  at time of sprocket collapsing.
Curious of rpm at time of failure , could help explaining other damages.
I had made same mistake tightening the nut ,but I heard it crack. Replaced it and was more careful with second install. The sprocket is fragile and cheaply made. If I knew about these failures at the time of build I would have welded that pin to the crank half. Easy to make that mistake but very costly consequences. Good luck & glad you weren’t injured.

Now I'm worried. My 05 that I bought back from insurance suffered a sudden stop on a car,at 45, the forks snapped off and the end of one took a chunk out of the lower front of the case. I don't see any signs of oil,.. But I also have been in the cam, the clutch, and I used my impact. But I was not seeing how much I could tighten.. But it's Easy to get seventy foot pounds with a quick blip.
I don't Know if I should trust that motor. It's got my cam in it. It's not the best one, don't remember which it is.

Any updates on the rebuild?

Celeste was last on the forum 6/19........wonder if the rebuild project ever got completed?

Celeste wrote on 08/09/23 at 16:19:57:

Here's the problem, the 97 rotor has different ignition timing then a 87.
Find yourself a 89 or earlier rotor or put a CDI from a 96 or later and you'll be fine.

BTW; the 96 or later CDI takes a different plug.