The file was created as a .xpm file, thanks nohal.
I can see the shape i created, once opened in a text editor.
Better yet, i could remove imperfections (just drew some lines for this example) this way.
kept complaining about not type 9, this was solved
by removing the other files (which i obviously left in the folder) from the folder.
Also, the file will only be accepted as ownship.xpm, so Ownship.xpm will not work.
Also, when creating your own ship, you should use a transparent background.
Else you'll have a (probably white) square box surrounding your custom ownship shape.
So now i can use my own shape if i feel the need to it.