Removing OEM step bars - what to plug bolt holes with?

Sorry, not a highly technical question: I ordered rock sliders for my Taco and now I’m going to remove the dealer-installed step bars.

I would like to replace whatever plastic or rubber plug was covering the bolt holes in the rocker panel where the OEM step bars bolt on before I spray on some rust proofing.

Unfortunately Toyota Parts Direct doesn’t show what was there. Anyone know off-hand what was there from the factory, or be willing to go have a peek at their truck? A part number would be even better!

Thanks!

 

1. Remove step bar bolts.
2. Remove step bars.
3. Reinstall bolts from step 1.

 

Silicone. Ideally, the factory bolts but they went with my factory running boards so silicone it was.

 

I might have them if you want. Itll take me a while to find them though.