Just be aware that there are two very similar looking cam cancellers. One is for tilt and the other is for non-tilt.
Turn signal cam and springs are available at Advance. Dorman products. Most parts stores carry the Dorman line. The horn ring is used on many GM vehicles. It's not listed for the Fiero but the S10 uses it. The white one is for tilt columns, the green for non-tilt.
http://shop.advanceautopart...am-83232/17190463-P# I know it says it won't fit a Fiero, but it does. I have two in use at the present time.