I totally missed this last year, but apparently CalTrans had one of it's F59PHis rebuilt as a V12 ECO unit. Sacramento Press / Amtrak locomotive gets an eco-makeover At the time, plans were to upgrade the entire fleet.
I missed this too. Everyone was paying attention to KCS - but that should've meant someone noticed this.
I don't think it was the only one to get an ECO make-over. Those F59's came in to Chicago one at a time on either the Zephyr of SW Cheif through out last year. Some of them got rebuilt at EMD in LaGrange while I think some went to either KC or St. Louis to get done. Several of them sat at the Congress Park yard after being dropped off by the IHB to the BNSF, wish I could find the pics I'd post them.
The article states that CalTran's fleet of I think 15 was all going to get the treatment, but the article is from a year ago, so I would not be surprised if they all cycled through...which of course makes it all the more odd that it wasn't picked up on.