William Brough who was a 9 year old with Thomas and Agnes Gelling in 1841, is probably the William Brough age 28 in 1861 with wife Jane and family :

Ancestry 1861 IOM Conchan, district 2b, page 46
8 Hanover Street
William Brough Head age 28 Miller born Scotland
Jane Brough wife age 29 born IOM
William W son age 7 born IOM
Sarah A dau age 2 born IOM
John J son 4? days born IOM

Sarah A is Sarah Anne, and John J is John James (from IGI)

William Brough married Jane Preston 12th Oct 1853 Braddan

The IGI has this William Brough born Scotland in 1833 with a father James Brough:

WILLIAM BROUGH Pedigree
Male

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Event(s):
Birth: 01 MAR 1833

Christening: 17 MAR 1833 Perth, Perth, Scotland

Death:
Burial:

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Parents:
Father: JAMES BROUGH Family
Mother: JANE WATT

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Messages:
Extracted birth or christening record for the locality listed in the record. The source records are usually arranged chronologically by the birth or christening date.