#orders it from London; gets gently scolded for the expense (but she lets him carefully rub it into her skin all the same)

[marzipanandminutiae]

Were moisturizers hard to come by in the 1880s? I am wondering why Mr. Cushing (although I love how wonderful he is as a father) was so judgey about Thomas's soft hands. Like he's rich (esp. compared to the broke-ass baron), and calluses don't last forever, he can definitely afford lotion and he is shown to enjoy self-care. Also, I highly doubt he is doing the hard labor of his company in his mature age. That scene makes me be like "WTF do you have against moisturizers?!" Am I missing some context in this?

Not remotely. Nor yet in 1901, the "present day" of the movie. Even many poor people could get their hands on a basic Animal Fat + Possibly Some Sort of Scent concoction, and the likes of Carter Cushing could afford to patronize shops on the cutting edge of Victwardian moisturizing technology. Plus, as you say, he's been wealthy for at least 24 years, and therefore presumably not doing manual labor.

So what's going on here?

My guess: the Doylist reason is that they didn't think that hard about the logic of a single throwaway line. The Watsonian reason could be simple vanity. He wears fine clothing because he's somewhat vain, but perhaps paradoxically refuses to use hand cream for the same reason.

Carter resides in that awkward space of the Gilded Age self-made industrialist (with the difference that, unlike many of his peers, he actually is self-made). He is rich, he wants to enjoy the benefits of being rich, but he also has a tremendous amount of identity tied up in his humble beginnings. He wants to be seen as simultaneously the salt of the earth and a man of means. Hence, maybe, an up-to-the minute suit in the finest fabric and hands studiously ignored.

...or he could have been talking about scars, arthritis, bones broken and reset in slightly off ways, etc. Permanent alterations due to manual labor. That raises the question, though, of why Thomas' hands aren't at all "rough." Clockwork and machinery aren't exactly forgiving in that respect- springs snap back and cut you, sharp or heavy tools slip, turning cogs pinch fingers. It's a miracle that his burn in the movie was the first such, if that was indeed the implication.

Then again, I suppose Carter doesn't have a borderline-genius Home Chemist(TM) tirelessly caring for him. I'm sure Edith is concerned with his welbeing, but I don't see her spending much time on nursing or in the stillroom beyond learning the basic household first aid expected of a woman back then.

I bet Lucille's hands are rough.