I think the other locomotive is the Leslie, which was the 2nd #1, originally built for the Kahului & Wailuku on Maui, and coming to the Hawaiian Railroad (before it became the Hawaii Railway) in 1884. It's shown
here as being at the Bothwell estate with an added note that it was "Sold at auction in November of 2017 for $187,000.00" According to Railroads of Hawaii, a "commoners" car went to Bothwell along with the Leslie.
The #5 is the one that is now in Connecticut. This is a newer locomotive built for the Hawaii Railway. There are details of its travels
on this site.
I've looked for the
dumped loco, but does not seem to be accessible (see the notes accompanying the photos at the bottom of
this page). To reach the site where I understand it to be located along the grade means passing through private property, very close to homes. I was able to get the the the gulch it's in without trespassing, but it's a steep gulch and jungle conditions. I couldn't see any sign of the grade from the end of the road.