[chris vickery]

One website I visited recently on this issue suggested that lining are available in a variety of widths and thicknesses by the 1/8".
Since military drums are so heavy and likely original diameter, a quick turn with as minimal skim as possible should even them up. If originals were 3/8" maybe it is possible to use 1/2" linings by removing adequate material to suit.
I had CMP brakes relined this way with lots of material left on the drum.
When you consider how thin modern drums are, the old military ones are built like tanks. Also, the vehicles we are putting them on are not seeing service conditions loaded to the max or overloaded even. For something like a carrier I personally wouldn't get overly concerned as long as you get new shoes to match up to freshly turned drums.