[Heathkit] Help with SB-401 plate,driver,osc slugs???

[Dan Pividal]

Well, I am doing an alignment on my SB-401.
80 and 40 meters was easy.
Each band had visible coils in the plate,osc and driver sections inside the 
metal compartment beneath the finale rod going to the finale compartment.
However, in the plate section and the grid section I don't see the same type 
of coil in the 28.0 or 21.0 holes of either section.
I do see something way down the holes almost even with the floor inside the 
metal box.
Are those tuning slugs?
The manual says to peak grid, plate and osc coils.
I will not do anything until I hear from the list.
Thanks,
Dan/N4VET