"My gut tells me that hub should be mounted on the outside of the drum, like original."
Listen to your guts on this one.
You will have to press out all of your lugs from the hub, and then put the drum inboard of the hub so that the the drum will index on the hub, then press the lugs into the hubs again. Your drum will then be sandwiched between the heads of the lugs and the inboard flange of the hub just like the original.
I would recommend mocking up just one lug, then mount the rim on the assembly to ensure that your lugs are long enough.
Carl

1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission