Finally, a proper answer to this query: the Manchester set and the 2487 set used some of the same pieces, but not all of them!
It appears from a careful look at the most recently posted Sowerby catalogues on Mike Tomlin's website, that Sowerby created different combinations of pieces and depending on whether they were 5 or 7 piece sets gave them different names.
So, the Manchester was a 7 piece set (with a choice of tall or short candlesticks) and 2487 was a 5 piece set (with the short candlesticks). Confusing, isn't it?!