Regarding Tom's elevator trim device, 80 to 210 MPH IAS isn't enough.

Even my very early 235 has a wider speed range than that. Level slow flight
(just above the stall buffet) is around 70 - 72 MPH IAS and VNE is 247 MPH,
to which I have tested (plus 10%). My stronger than original trim springs
will trim that range. 320's and 360's probably have a higher VNE (I've never
checked) so most likely need even more trim authority range.

Dan Schaefer