When was the white face paint scheme initiated on BN on any engine, not just the SD40-2? When did it end? Are there any white face units to be seen anymore or are they all painted? Thanks.
Yes, they used it (in both the pinstripe and non-pinstripe versions) on all non-AC power up to the merger. Many units remain in the scheme; I don't know if any are unpatched.
This link shows what you need to know: http://www.fobnr.org/motivepower/whiteface.htm Loads of ex-BN whitefaces are still around--rent-a-wreck leasers, and BNSF patch jobs as well. Here's some 2008 captures:
There was about 50 or so GP50's painted with the Tiger Stripe nose and "Tyco" lettering. Some of the striped GP50's kept the "Tyco" lettering but had the whiteface applied to the low hood and cab. Here is a photo of two GP50 paint schemes. just my 2 cents worth