Hi Al,  My suggestion is that you capture the change order with change order #1 for  PSCO's break out contract.
If it needs to be paid before year end (which it  probably does) you can put a payment date of December 20th, and it will be  paid out of TurboPark.
This approach has been discussed with Lee Johnson at  GE, and he is fine with it.
Thanks,

Change order to GE contract for PSCO changes