When Did They Stop Making Paper Shotgun Shells?

These water-resistant, wax-impregnated paper shotgun shells were introduced in the 1870s as a lower-cost and lighter alternative to brass shells. Paper shotgun shells remained popular until the 1960s when plastic hulls took over the market.

Are old paper shotgun shells worth anything?

The "old" shells probably are not worth anything. Depending on just how old they are.

Are 30 year old shotgun shells still good?

If the shells are black powder, say from the 1880-1920 period, i'd advise that you not use them. However, if they have stored properly and not corroded, they should be just fine.