I believe that am descended from James's (twin?) brother, Thomas Maddrell. He bcame one of the guardians of the four children of James & Margaret (see Margaret Maddrell will 01060407 on Brian Lawsons's site). Note that this was transcribed by George Callow (family?).Unfortunately there appears to be no will of James or Ann Maddrell (Collister). The 1832 will on film number 0106247 appears to be that of Ann Maddrell née Kermode, although it has not been transcribed yet. The James & Ann had a son, Michael, christened in 1806.
Only one other James, on the IGI and born in Rushen would be of marriagable age in 1803. He was christenen in 1755. I will check the Rushen monumental inscriptions this weekend.
Bruce.