If this works the backing plate needs about 1.75" spacer
I'm thinking that spacer needs to fit tightly on the axle and be made of some substantial stuff, because the last thing you want is your backing plates moving around and breaking bolts or brackets.
How would you feel about actually welding the spacer to the axle?
Does any of the brake mechanism move into possible contact with the hub as the backing plate moves outward 1.75 inch?
Do you know what year your axle is? I just looked up brake drums for mine on Rock Auto using a '79 P30 as the vehicle and found the same drums used across a number of trucks from '73 to '84. The pictures look like the same drums you found at NAPA, though I don't trust parts dealer photos quite that far.
We are supposed to have temps in the 40's today and I'll try to get outside and look at and measure things. Otherwise I'm back in the hospital tomorrow and away from my toys at least a week.
