Afaik it's 40d9, I had to adjust tweak to get it working for 40d9.
If this is set to YES, the tiles will not be stretched, but rather the game view will be centralized, surrounded by black space. Tiles that are too large will always be compressed rather than running off the screen.
Graphics info, most of it as above. Set GRAPHICS to YES to turn it all on. This will use the "raw/graphics" folder for tile information. Currently this is limited to whatever creature graphics you have downloaded. The game comes with a few pictures to demonstrate. As of September 2008, the Dwarf Fortress Wiki has graphical tilesets available at http://www.dwarffortresswiki.net/index.php/List_of_user_graphics_sets.
This is the dimensions in tiles of the display grid. Minimum x is 80. Minimum y is 25. Maximums are 200. Make sure the window size or full screen resolution matches the grid/tile size if you don't want the display to be squashed or stretched. The default windowed font has tiles that are 8x12 pixels, for instance, so for a 80x25 grid, you use a 640x300 window, and for a 125x50 grid, you'd use a 1000x600 window. FULLGRID is used in full screen mode, whether graphics is on or not.
^^^ that should pretty much set you up since we both use the same vertical resolution. If it looks stretched horizontally just set black_space to yes.