Common GraalEditor problem

[hhdoubleharrasholy]

Ah you're the man. +rep fosho.
Another quick question, era uses different tilesets, if I wanted to use both would I just add the tiles in the empty spaces? And it would transfer over nicely?
If I was to submit this level would I have to change the tiledef so the staff wouldn't have too? I'm just trying to pick up all this general knowledge in quick time.