That is some good info. CCF - old split rims are nothing to fool with.

I had a 3 piece split rim explode on me with 95 lbs. of air in it. I know because I had just checked the pressure - luckily for me it was in a cage. The cage was destroyed but all I got was a bad bruise on my right hand.

All of the split rims were fine when designed and built. The problem comes when crud builds up inside the groove for the split rim to seat in.
That's what happened to me. Needless to say I will never air up another one that is not in a cage.