I can't find any connection to Peel and the harbourmaster at Douglas (a fairly high status position) would not live in Peel at least pre 1870s as communication would be difficult - what is your source for this ? - the main link I can find is with Ramsey - there are a couple of families with burials at Ballure + pre 1841 a Cath Roxborough had a number of illegitimate children

The only Manx born Roxborough in 1881 census was John age 60 born Ramsey living in Kirkdale (nr Liverpool) (prob son of George R. + Elizth Harpur)

In 1881 census the Roxborough family in Douglas was headed by a Henry Roxborough fish hawker born Ramsey - there is a small number of burials in Maughold pre 1860

The last male Roxborough burial was a George age 65 in 1928 at Braddan (Douglas)

Don't forget the Manx Museum library which has all records pre 1911 is closed Mon + Tuesdays