Re: Northern RR (Costa Rica) Roster - book?

The original name of the "Atlantic" line in Costa Rica was the Northern Railway of Costa Rica (3'6" gauge). In addition to the Pacific Railway, there were at least three other (banana) lines in Costa Rica, but I never heard of any Hawaiian engines on any of them, but that's not to say it didn't happen.
I'm guessing, like some others, that the engines your are looking for are the four Oahu engines that went to the Ferrocarriles de El Salvador (32, 34,35 and 36). As Tom mentioned I photographed one of them switching at Sonsonnate in 1968. I visited the FES fairly regularly between 1968 and 1980, and that 1968 visit was the only time a saw an ex-Oahu engine active.
John West