Perhaps someone's already done this long ago? If not, here's my best guess for the John Cain who was Liz's gt grandfather in 1891, after analysing the census pages of all the John Cains in the right age group. I've ignored the ones with a middle name that's not Henry.

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From Brian Lawson's census index:

1891

CAIN John 35 Douglas 4689 123 32
CAINE John 34 Vessels 4692 99 67
CAINE John 33 Douglas 4689 43 28
CAINE John C 33 Michael 4683 128 40
CAINE John James 32 Douglas 4689 41 12
CAIN John J 32 German 4682 100 58
CAIN John W 32 Lezayre 4684 144 55
CAINE John T 31 German 4682 70 35
CAIN John 30 Douglas 4687 39 18
CAINE John 30 Vessels 4692 106 134
CAIN John Herbert 29 Douglas 4688 75 177
CAIN John 29 Douglas 4689 85 195
CAIN John 28 Douglas 4687 3 1
CAIN John 28 Marown 4683 82 43
CAINE John 28 Vessels 4692 101 90
CAIN John 27 Douglas 4687 24 38
CAIN John 27 Douglas 4687 33 154
CAIN John 27 Douglas 4687 91 121
CAINE John 26 Vessels 4692 102 96
CAIN John J 23 Douglas 4689 10 113
CAIN John Thomas 22 Onchan 4686 103 121
CAIN John 22 Onchan 4686 112 78

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CAIN John 30 Douglas 4687 39 18

Onchan 3/3

b Baldwin, coal cart driver. Wife Mgt. Chn 10 down to 4.

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CAIN John 29 Douglas 4689 85 195

Onchan 21/30

(indexed as John N Cam by Ancestry)

This is John Nelson Caine and Martha Dobson

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CAIN John 28 Douglas 4687 3 1

This index is for a 23 yr old, engine and machine maker, living with parents Thos+Mary

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CAIN John 28 Marown 4683 82 43

This John is a plasterer b Jurby, living with mother Maria

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CAIN John 27 Douglas 4687 24 38

33 Barrack St

John Cain road labourer b Douglas

Name Age
Timothy Bryan 65
Elizabeth Bryan 62
Henry Watterson 73
John Faragher 70
John Cain 27
Stanley Dougherty 30

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CAIN John 27 Douglas 4687 33 154

John Cain b Peel with wife Julia

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CAIN John 27 Douglas 4687 91 121

John Cain b England, oyster dealer, with sister, Jane, and mother, Ann.

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CAIN John J 23 Douglas 4689 10 113

John J Cain b Douglas unm grocer's assist, father John Cain.

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CAIN John 22 Onchan 4686 112 78

John Cain ag lab on father's farm, b Onchan, father is John Cain

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Conclusion:

The 27 yr old road labourer living on Barrack St looks the most likely.

Jean C