I am seeking information on a Korean steam locomotive of significant notoriety (which, unfortunately, I know too little about to know where to direct my research)

The locomotive in question was based out of the Seoul roundhouse during the Korean War and rebuilt by the U.S. Army's 724th Transportation Batallion out of Fort Eustis, Virginia. The locomotive (while of Asian manufacture), following its rebuild, was said to be largely American in appearance and was given the name "Tamalpais" by the 714th's Chas. Ward of Los Gatos, CA.

There were reportedly newspapers in the Bay Area which displayed a photo of this locomotive, probably for that its namesake of course lies in Marin County. I would also be interested in knowing if perhaps this locomotive still exists in a museum/other state in South Korea.

Any leads greatly appreciated

Well here are some sites that may be some help.

North and South Korea Steam Locomotives, and their histories.
http://www.pernet.net/~james1/us_steam/korea.htm

Steam locomotive of South Korea National Railway, still operating.
http://www001.upp.so-net.ne.jp/noz/korea/ekr-idx.html

Nice site on USA steam loco’s from Ft.Eustis and where they went or are today.
http://donsdepot.donrossgroup.net/dr109.htm

Hope this helps you in the right direction.
Steve