Null Tile Value in Castle Exterior, Rural Tileset?

[Legacy_BelowTheBelt]

               

Anyone know what a null tile value would be for the Castle Exterior, Rural tileset?  I've played around with it but can't seem to find one and there seem to be hundreds of values.  I was hoping someone else would have found it.

 

 

               
               

               
            

[Legacy_Zwerkules]

               

Huh?? I have no idea what you're talking about.

               
               

               
            

[Legacy_BelowTheBelt]

               

For GFF editing inside the tileset.  I don't know the range of the tile values in the Castle Exterior, Rural tileset.  I'm trying to find a blank tile value that won't crash the system.  I've been manually trying to find a value that is in-bounds, yet unassigned (and therefore 'null').

 

I need to get a blank (grey void) tile for some in-game visuals I'd like to build.

 

That help?