I made a few bead models of [n]-circulene (n=5,6,7,8) to illustrate the influence of nonhexagon on the local Gaussian curvature at nonhexagons.
One can easily see that -circulene (coronene) is planar. But -circulene (corannulene) has positive Gaussian curvature (bowl-shape), and - or -circulene have negative Gaussian curvatures (saddle-shape).
I made these models for the workshop for the 21st International Conference on Chemical Education (ICCE) yesterday after. However, I don't have chance to use them.