From what I understand thus far (or what I think I understand!), the lions share of the work in celestial navigation is not in taking the sights, it's everything else before and after that. Working with the sight data, times, tables, charts, a little basic math, etc. So yes, I'm sure I could get by with even a cardboard sextant. But admit it, putting that up for display on the living room shelf is going to be a tad on the cheesy side. I guess you could put it up next to the telescope you made from a wrapping paper tube.