"Carryover page? carryover part? 55-59 manual shows switch . . . "
What 55-59 Manual? Is it on-line?
The 1955-2nd Task Force switch shown at a link in my post above is no "carry-over" from the 1955-1st Advance-Design switch (they have significantly different overall appearance/design - the 1955 Task Force switch compared to the 1955 Advance-Design switch).
That 1955-59 Classic Parts switch is an aftermarket switch. However, it might indeed look like the original 56-59 switch?
I'll look at GM manuals tomorrow to see what they might show/describe for 1956-59, unless someone posts a link to one of those Chevrolet Truck Manuals.
