Mea, I was just having a quick look at it. I got the same as you, but couldn't decide if that was a gate (late-ly), or a wall (all). Either works I suppose.
I remember doing this as a youngster! Encrypted letters...very spy-like.
I love the doodles. Might save it and see how far I can get with it.
Thanks Foto, exercise for our artistic brains!