Bearcat, he said he can jump the starter just not thru the key, so not likely it’s the starter. Solenoid has been replaced, that leaves neutral safety, kill switch, or turn key, or a fuse.
If you can jump the two wires coming out of safety neutral switch that will bypass that, sometimes the control arm that ground out the plug can gunk up over time and not disengage. Kill switch would be pretty weird to just go out and not work, as the key suddenly stop working as well. Critters chewing something also comes to mind, especially if it’s sitting.