In the last hour I've been cutting out the old lower latch(welded in at factory).
I had 2 very artsy ideas pop into my head.
1 just put a very good coat of White paint on the back wall and then paint some
Roll up door seams across horizontally, bolt the hinges and other hardware back on including the handle and Latch .
From a distance it would look like I Just installed the window in the roll up door.
2 Do the same with the smooth wall except,,,,,Take a pic of a Empty box truck and have a wrap (a big Decal) made from that pic. Now this would look really weird like the window was hanging in mid air