For those who are using GRPViewer's "Find map by a given TileNumber" tool: the current GRPV version doesn't search for floor and ceiling textures (my fault).
Those who are brave enough may download the fixed version of GRPV - search includes sprites, walls, floors and ceilings. Before You start... copy palette.dat from SW folder (extract from SW.GRP if needed) to GRPViewer's folder replacing the existing palette.dat for Duke3D.
Warning: this is unofficial release for people here reading this topic... It's totally undocumented and untested... The HRTT, model tool and skybox tool are for previewing purposes only.
Gathering Of Bugs Entertainment proudly presents:
GRPViewer (unofficial)