I used Timothy G.s suggestion (which worked - thank you!) and took it a step further.

I overwrote the VCToolsVersion and VCToolsRedistVersion in both the default AND base platform props/txt files in C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Auxiliary\Build

I still had selected v143 in the Platform Target Toolset in the C++ project properties (in visual studio - so no changes to project)

I took the VCToolsVersion and VCToolsRedistVersion info from this:

and overwrote the VCToolsVersion and VCToolsRedistVersion info in these files:

bingo bango, project builds perfectly.

This allowed me to build our legacy programs without making any changes to the project itself. Our company is forced to use out of date toolsets due to some other software we integrate with that isn't up to date... And many of our tools are used in that software...