Hi - The difficulty is not when each James died, or who they married, but who their parents were.
You are right that your James, ropemaker, was the one who died in 1852. Other James, 73, is in the 1861 census still in King St., Ramsey, still proprietor of houses, b.Maughold, and presumably was the one who died in 1871.
I overlooked his "b. Maughold" in my last message, and now think he is most likely to have been the son of Daniel Callow & Mary Kneale bapt Maughold 16 Sep 1787. - The only James Callow bapt in Maughold 1786-90.

Two possible marriages to Isabella (aged 54 in 1851 & 64 in 1861). James Callow & Isabel Quayle 3 Oct 1815; Isabel had consent of parents, and James Callow & Isabel Lewin 19 Mar 1815. Probably the former, because James would have been aged 28 and she was about 9 years younger.

Your James Callow b.Ramsey is more difficult, with the two possible baptisms. James bapt. Ramsey 4 May 1788 the son of James Callow & Esther Lord, and James bapt 4 July 1789 Ramsey, the illegitimate son of Margt Callow. Ignoring his age in the 1841 census, his year of birth was given as 1791 in 1851 and 1788 at burial. He could be either James.
A James Callow died of smallpox and was buried in Maughold on Dec 29 1822, and another James Callow was buried in 1825 (no ages). Ramsey burials are mostly not indexed, and I have only Maughold bapts, not Ramsey ones. It could sort out which Ramsey James Callow was your ancestor if you look at the Ramsey parish church register at the MM Library or on LDS film no.106741 at any Family History Centre worldwide (see Church of Jesus Christ of Latter-Day Saints in the phone book - open to all, no charge apart for a small fee to bring the film to your local FHC). The register could give extra details for his baptism, and you could follow the two possible families back through bapts marriages and burials.
The good news is that there is a will for CALLOW, James, 1852, Maughold, E[pis], [no.]64, [LDS film no.] 0106452 which could name siblings, as well as children, etc. This can also be ordered to view at a local FHC or at the MM.

Sue