"Scroll" as in the decorative curlicue element in a "wrought iron"
fence. I need to replace (match) 2 missing ones. I have a loose one to
use as a pattern.

They will be made of 3/16" x 1/2" mild steel. The largest diameter is
6" & there are about 1-1/2 turns. After a 1/2 turn the diameter
decreases by 1/2 (is that a standard for scrolls?).

Should I heat them? (I have a propane foundry burner that I can cobble
into a forge.) If so, how hot?

Will I need forms to bend against? If so, is there a rule of thumb for
the spring back to account for (hot, cold)?

Any tips about stuff that I don't even know enough to ask about?

Thanks,
Bob