I have a vintage cloche pattern from 1931:
(I apologize for the quality of the picture)
I'm guessing that the pattern gives two different versions of the same hat, because there's another picture that shows the hat with crocheted leaves instead of ribbons. In any case, you could probably leave the embellishments out, if you'd like.
Here are the hat's stats:
Measurements: Round head band--22 inches. Can be arranged for a slightly smaller size or to 23 inches.
Depth from the center of the crown to the edge of the front--8 inches.
Depth from the center of the crown to the lower edge of the back--9 inches.
Tension: 10 d.c. to 1 in. in width
10 rows to 1 in. in depth.
If you're interested, let me know and I'll type up the rest of the pattern for you.