^^^ this ^^^
Are the stud holes in the aluminum wheels roughly 14mm like your wheel studs - or are they significantly larger? If they're larger, they almost surely require a shank style lug nut. This solves your wheel stud issue because a good portion of the lug nut threads go through the wheel instead of simply sit on top of it.
Here's the type of lug I mean - the shank length is .80" so that correlates to your .89" for the outer wheel; you don't want it to be the full .89" or it may bottom out on the inner. The steel inner should have holes close to 14mm and be hub-centric.
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Those inners look weird, too. Do you know what they're from, or did they come with the 19.5's? The thickness of the mounting surface of those seems thick, but I don't have a measurement handy on the stock 4-holers from my '93 to compare.
Richard