BOY CONVICT JOSEPH MAWBEY AKA JOHN MORBEY

Thanks to the generous Australia Day gift of Ancestry.com.au to free access to their convict records for three days, I think I have tracked down the boy 'Mawbey' convict.
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I found details of a 'John Morbey' who arrived in Van Diemen's Land in 1833 in two records:

• Australian Convict Transportation Registers, Other Fleets and Ships, 1791-1868
• New South Wales and Tasmania, Australian Convict Musters, 1806-1849

He was convicted at Leicester, Leicestershire, England on 1-7-1833 and departed on the John on 3-8-1833 and arriving in Van Diemen's land later that same year.
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He was subsequently convicted again in Hobart.
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Finally finding this out feels like a major breakthrough!
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He is not listed on either the Tasmanian Archives or Queensland Library convict registers under this spelling, Morbey, of his name.
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If he was aged around 10 in January 1835 when he was in Hobart court, he was only eight at the time he was given a 14 year sentence in England.
What on earth could he have done to merit such a harsh penalty?

If the young John Mawbey was already a 'prisoner of the Crown' when he was before Hobart Quarter Sessions for stealing from shops (shoplifting), what was he doing roaming freely around the town?
Why wasn't he incarcerated?
And why wasn't he incarcerated when he was let off the first time he was before the court?
He must have been an escaped criminal at the time ...

WHICH JOHN MAWBEY WAS TASMANIAN FAMILY FOREBEAR?

I've been discussing the three Mawbey males known to have been in Van Diemen's Land (Tasmania) on my Mawbey Family Australia - Victoria blog, trying to work out if they were related.This prompted me to take another look at the family tree I had been sent by a descendent of the Tasmanian Mawbeys.
I had taken it to indicate that the male forebear, John Mawby, had been the 18-year-old convict who had arrived in the penal colony in 1842.
But now I'm wondering if he was in fact the John (Joseph) Mawbey who was the 10-year-old convict before Hobart Quarter Sessions in January 1835.
Judging by their ages, the former was born c.1824 and the latter c.1825.
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The Tasmanian Mawbey family historian said that John (Joseph?) Mowby was born in 1821.
He entered into a permanent relationship with Maria Inglis, b. 1836, and they produced at least one child, a son Nathan Mowby, b. 14.12.1874.
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So John Mowby was 15 years older than his partner.
There is no marriage record, but Maria died named 'Mawbey'.
If they paired up when she was 20, and he was 35, this would have been in 1856.
But their son Nathan not born until 18 years later, when she would have been 38 and he 53.
There could have been another generation in between.
I will have to check this.
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The Tasmanian Mawbey family historian appears to think her forebear was the John Mawby who arrived in 1842.
The convict boy, John Mawbey, was sentenced to 7 years transportation in 1835.
If he was sent back to England, he may have been the same one who arrived back in Tasmania in 1842.
Both of them were convicted of stealing, and coincidentally, both had stolen shoes.
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I have not been able to find any records on any convict registers of the convict boy who was in Hobart in  January 1835.

I've been reading through some material about the Mawbey family in Victoria that I was sent months ago by a fellow family historian.
There I found a reference to a young boy aged 10 who ran away in Tasmania and spent two years with Aboriginals.
Could this have been Joseph Mawbey?