how to read these coordinates

[Waterlink]

Hello, my wife and I are trying to find the location of a property in the Philippines. Along time ago she paid for a share but the seller disappeared without notice. My best efforts to read these coordinates locate me to somewhere in Botswana, along way away from. Lapu lapu in the Philippines.
Any help to read the attached picture

is much appreciated.

 

[Nuvi-Nebie]

I don't think the coordinates are Latitude / Longitude, I think they are Northings and Eastings, this is where the world is divided into squares like in the UTM system where Lapu Lapu would be in UTM zone 51P, a corner of this square would be the starting point to count a number of metres North and number of metres East, however I can't make the figures work

 

[Nuvi-Nebie]

I have determined the shape of the land, if you subtract 1716254 from the Northings and 1821716 from the Eastings you get these figures :-

When you plot the new figures on a grid you get :-

Do you know anything about the plot of land ?, does it cover an area roughly 75 by 50 metres ?