Ah of course you mean just like trouser cuffs, so I'll turn the cuff back up inside sleeve and them sew lining over fold cool !I'd say it took me about 20 hours off and on for a few days,
as for those cuffs it's hard to say, it almost looks in the picture like it was folded back like a pant cuff would be, but in that case you would have to turn it wrong side out to sew that curve in, otherwise on the couple pieces I have with cuffs like that they were usually backed with a different material that you would just sew to the raw edge of an unfinished cuff and have it roll back inside,
don't know if i'm describing it quite adequately but if the sleeves on your jacket are too long it shouldn't be hard to do