~~ MALACANANG GARDENS LINE ~~
Klarence Pitoc has brought up the Malacanang Gardens line today which set me Googling again.
At first wondering how it could have got there from Pandacan, but then decided to revisit the fuel branch again.
Continuing on from the terminal it does seem there is an obviously likely route for the balance of this line.
See green line below for what I assume to be the case - Corrections welcome.