Re: HISTORICAL MISSION *LINK*

Ron,
Your question is a reasonable one. It's fairly certain that limited concessions to modern technology have already been made on the D&S. Certainly welded repairs are now routinely done to boilers that would have been impossible ~50 years ago. No doubt modern lubricants and other materials are used. The question is really "how 'authentic' do you want to keep the operation?"
I submit that converting operating locomotives to GPCS coal firing could be done unobtrusively, and in a manner that could be relatively easily reversed at some later time if desired. Not only would pollution be reduced, but operating efficiency would be considerably improved. I'd certainly rather see these locomotives burning coal relatively cleanly than converted to natural gas or diesel oil.
BTW, in the 1990's, Porta did quite a bit of work on minimizing coal smoke from steam locomotives while standing and starting at the Teresa Christina Railway in Brazil (famous for its U.S.-built NG 2-10-4's). This info is probably not that hard to come by and would likely be much easier and cheaper to implement than stand-by natural gas firing systems, etc.
Hugh