Thanks for the replies. I did look at the names of the marriage witnesses but none of them proved helpful. I haven't seen the marriage bond (I couldn't find it on Findmypast) but Wm Maskery isn't a name which seems to lead anywhere.
The best bet for James's baptism seems to me to be in Kedleston, to James and Ann, 25/3/1759. It's about 11 miles from Rocester and Marston Montgomery, 9 miles from Cubley, but only 3 miles from Brailsford. Family names include Ann, like his daughter. And the date seems right. But I can't rule out the several others which seem plausible, so a brick wall it remains...
Thanks again, and any further thoughts very much welcome!
Andy