They look like the screws that go into a ground bar/buss bar, possibly near the converter.
Your screws have a yellow zinc dichromate finish that are often used.
ON EDIT: They were probably in unused holes but if they vibrated out, I'd be checking the ones that have wires under them as well! That was some rough road!
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2022 Cedar Creek 345IK 5th Wheel•Solar & Inverter•2024 Ford F-Series SCREW•7.3L•4x4•Factory Puck•B&W Companion•TST Tire Monitor w/Repeater•Sinemate 3500w Gen.
F&AM Lodge 358 Somerset, PA - JAFFA Shrine - Altoona, PA
Days Camped ☼ '19=118 ☼ '20=116 ☼ '21=123 ☼ '22=134 ☼ '23=118☼ '24=90