The last vane-type indicator I witnessed was hanging on the strut of a
New Standard DB-25 (circa 1926). It was an airspeed indicator and
appeared to function quite well from my perspective in the forward-left
front seat.

Orville Wright used a vane-type device in the autopilot system he
invented. While this was the world's first functional autopilot, it
never became popular. Sperry's gyroscopic autopilot system hit the
market shortly after, and was superior.

I'm not familiar with any vane-type AOA indicators that could be
mounted on a strut, but that doesn't mean that they didn't exist. If
anyone knows of one, I'd like to see it.

Harry