[HAM] Holes near the legs on the bottom of a B3

[David Harnett]

I am cleaning/inspecting a B3 that I recently acquired, and I see holes 
an inch or so away from each leg on the bottom of the B3.
I can only see a little way in the (counter-sunk) holes, and I do see 
some threads. My head is against the leg and I can see no further.
Does anyone know if I am missing some bolts in these holes?
David Harnett