Thanks so much for the help. I am using 3.2 so I didn't have the property selections that you indicated.
I did find a solution, however. My platform is 64pix deep x whatever length, Im going in even grid increments (64 pix reticules), so I resized my main texture to 64x64, created a TextureRect that was 64 pix thick and 64 x N blocks long and set the stretch mode to tile. That repeated the pattern. It works, and Ive learned several things just with struggling with this.
I used to make maps for Counter Strike years ago and I was used to being able to apply a texture to a polygon and size it in the editor, so I thought that would apply here. I'm sure it does and I am having success but maybe what I remember with mapping tools is not the same implementation here. Just gotta learn!