Had thoughts of putting this under the classifieds, but thought the exposure here would be better. Nice little 1915 Baldwin needs a new home on the west coast. Track, turn table, cars, etc.

https://seattle.craigslist.org/sno/hvo/ ... 02685.html

Suspect it was converted at some point to the gas engine drive, not sure if its gas electric or mechanical at this point.

Weyerhauser Timber Co. Mill B Everett, WA
#3 Baldwin C/N 42217 08-26-15 7 tons 16 HP 24” dr BE (bp reads July 1915)
Silver Lake Kiwanis Club Everett, WA 1968
(Converted to Gas Electric with a Waukeshaw engine by Western Gear Corp. 1968/69 for use in Silver Lake Park.)
Elmer Ahola Edmonds, WA 1977+
Jim Plute Edmonds, WA 1987
For sale on Ebay with several cars 08-10-04 $25,000
For sale on Craig’s List 09-17 $14,000

Are we to assume that the round structure atop the battery box is the hood for the engine, with the balloon stack housing the muffler, or what?

Yes, the photos show the gas engine sitting pretty high and hidden under the fake boiler housing.

How did it get power as an electric locomotive? Or, was it battery powered?

It is right there in the specs "BE" (battery electric). It was one of seven BE locos used on the 30" gauge system at Weyerhaeuser's Everett, WA Mill B.