I am trying to create sidewalks for a european raceway/layout. I used some parts of a retaining wall that I had molded out of hydrocal. See pic. This is O scale and I need to make my sidewalks wider for light poles. I also have a problem of trying to extend my sidewalk around a street curve.

Other than hydrocal/plaster, is there any material that I can use that will allow me to "curve" my cobblestone around the bend on my street. I also need to make a transition where the sidewalks meet at the corner of my street.

Thanks in advance. Please see pic of the bend in my street. I also have a intersection where I need to transition my sidewalks.

Moderator note: moved photo in-line. Click on photo for larger version.