Ok so I wrote a script that puts the player way up in the sky facing down and have the WASD keys move a set distance along x & z coords.
Next I loaded the big escape fpm and deleted all the stuff that would not appear on a map (like plants, rubbish bags, characters etc), using the script described and a snazzy screen capture tool I started in the top left taking a snapshot every move and ended up in the bottom right, IIRC i ended up with 1700 screenshots!
Next I put the screenshots through Gimp in batch mode and cropped each screenshot down to a small tile about 60 pixels square.
So you end up with a big flat map of the level in hundreds of tiny tiles, then all you do is write a script to display the tiles on screen, the bevel hides the new map tiles being displayed and the ones scrolling off being deleted. I intended to created several different bezels and to have knobs and buttons on it.
The hard part is working out all the scaling stuff to get everything to scroll smoothly and not have any gaps or overlapping tiles. I did this months ago and tried to put it up on the store but it was rejected, I then realised I wasn't happy with it and am planning on a re-write to make it work properly at all screen resolutions and ratios, which it doesn't at present.
Of course I am "planning on a rewrite" for all my little projects, I keep getting side-tracked by even cooler things to play with.
Been there, done that, got all the T-Shirts!