Hi Ed,
... And you won't find mention of them in any of those sources, either.
My source is Hol Wagner. Hol is author of "The Colorado Road". He doesnt' mention the oil conversion in his book, either, as he only recently discovered this information. His sources are the original C&S AFE's (Authorizations For Expenditure) and contemporary accounts printed in the Denver Times. Just because there aren't any photos captioned as such, doesn't mean that it didn't happen. At the present time, there is too much evidence to deny it.
It really helps to go back to the source material rather than rehashing the same old chestnuts that have been written about over and over.
All of the B-3-C Class of the C&S (No's 4-10) were converted to Oil Burners when they were rebuilt. According to the Denver Times, the 4 emerged from the shop as an oil burner. This conversion only lasted about a year or two and they were converted to (and back to) coal.
Rick Steele