Your search for "kobaru equivalent" revealed the following:

Water Tank Ogoya Railway Kinpei Type : Kobo-Nanarokuni Finished product 1:87 1027

Kiso Forest Railway Tajima Type Gasoline Metering Car ver.2016 (Red Tank/Black Carriage) : Kobo-Nanarokuni Finished product 1:87(HO) 1057