I really don’t know how one could play skully on a manhole cover–in fact, I remember playing adjacent to one and avoiding it at all costs in fear of losing our treasured caps down the holes you’d find in it!
However, I don’t mean to say your brain is turning to mush… I can imagine a game being played on a manhole if it were sufficiently smooth (I’ve seen smooth ones). If you could tell us more about it–like what era you played it–we’d all love to hear about it. It’s great to hear that about any skully variant, especially outside of the NYC/Philly areas.
hmcnally [at] streetplay [dot] com