When did BNSF start patching?

I don't know where to post this, if this shhould go in the model railroad forum or not but I am modeling the transistion between BN/BNSF late 1996 to 1997, 1998. When did BNSF start patching it's engines. I am not talking about the "fakebonnets" BNSF did with the warbonnet paint and the BNSF lettering applied but am reffering to the ATSF yeloow/bluebonnet units and the BN locomotives. Any pictures from taht era would be appreciated.

I would think that the paint shop started patching units as soon as the merger was approved by the ICC and BNSF had come up with a consolidated roster numbering plan.

But I can't say for certian, I was a Freshman and/or Sophomore at Winona State University (Winona, MN) at that time and was more concerned with college coursework. (Mind you, I was still active in the railfan/model railroading community and tried to keep up on current events, but that was one detail that escaped me. Now, if you ask me about U.S. History from 1812 onward... )

Anyone else who kept tabs on this know when the patched units started cropping up?

BNSF 2099 was the first unit out in H1 paint in November 1997.

So my guess would have been about early 1997 or so.

having said that though, it appears that the 600 series remained in pure ATSF paint with no patch until about 2000!

Some units delivered in '97 were delivered in Warbonnet or BN executive paint with BNSF words on it and not ATSF or BN anywhere. 1997 was the start.

I hired out in 1997. At that time, there were special instructions about specifying engine initials as well as number. This was because there might be a BN 1234 and a ATSF 1234. The BN numbering system seems to be the one that was kept. It seemed like units in conflicting units were the first to get re-lettered. Santa Fe SD40's were put into the BN number series for their SD40's.
The paint schemes were weird for a while. I was hostling at Clyde Roundhouse in the summer of 1997. There were new C44-9W's arriving from GE. These were in warbonnet paint with BNSF lettering. We already had some previous orders in the pumpkin scheme. I will attach a link to show you.
http://www.trainpix.com/bnsf/ROSTER.HTM The 700 class came in the summer of '97, but the 960 class came in the summer of '96. This may have been due to the 700 class being Santa Fe specifications. The roster shows it to continue from the Santa Fe 600 class. I have run some of the lower numbered pre-merger ones. They had a different brake system. I don't know if the post merger ones changed ( as it did on the 200->8200 class SD75, with ATSF ordered units having 30 and BNSF ordered units having CCB). I am trying to see if I can explain why they would have ordered units in warbonet after already having units delivered in pumpkin.