The tab may actually be rusted away, but you could hit them with some PB blaster or Kroil and then tap them toward the center. One way or another they should come out. The square under the head may be binding in the slot, so turning may help, assuming you can grab them with pliers.


Kevin
1951 Chevy 3100 work truck
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1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car)
Busting rust since the mid-60's
If you're smart enough to take it apart, you darn well better be smart enough to put it back together.