Regarding the cause of the large cuffs, before your edit, your post said "the 'meaty part' of your wrists" not your palms. Did you send them measurements of your hands instead of your wrists?
If so, maybe that's where the Sam Cavato tailor measured. As we all know, most alterations tailors like to make jacket sleeves cover the hands a bit, since that's where most men like to wear their jackets. (Although, Thom Browne and the recent fashion swing toward extremely short, tight clothing is changing that.) In general, I think it's best to measure oneself. There was a thread here a while back in which people argued that tailors who aren't making the garment themselves have little incentive to do a good job and may even take bad measurements to get you to buy something from them.
And actually, even better than measuring oneself, imo, is to send measurements of a garment, particularly if one has a vision of how one would like something to fit. Body measurements are good only if everyone involved has the same idea about how tight or loose, long or short, the garment should be.