another David Sievwright

I was contacted yesterday by a Sievwright researcher from Australia asking about David Sievwright who he thought was his ancestor. I could see immediately he wasn't since it was the David Sievwright who went to New Zealand.
The only info he had was the notion that David Sievwright was Scottish, he had a wife Lilly Auld and their children Lilly, Jane and Charles born 1865, 1867 and 1868 respectively.
I found the birth of Jane with mother's name Lillias.
Then I found the marriage in 1863 which also gave a date of birth for Lillias of 18 AUG 1834. Wondering if she too was from Scotland I had a look on the IGI and yes indeed she was born in New Monkland to Lillias Russell and William Auld.
I did parent searches on the IGI for more children of David Sievwright and Lillias Auld and found younger children William, David, Margaret and Elizabeth.
Following Scottish naming patterns, the first child, a daughter, was named Lillias after Lillias Auld's mother Lilias Russell, the next daughter Jane should be mother of David and the first son Charles should be David's father,second son William after Lillias's father.
So we are looking for a David Sievwright son of Charles and Jean. Yes there is one born 1829 in Marykirk, Kincardineshire to Charles Sivewright and Jean Duthie.
Meanwhile in Australia the researcher has come up with a David Sievwright transported to Western Australia (where he is) in 1856 on the William Hammond. Lots of information on the convicts on this site
The ship sailed from Plymouth in January 1856 with 250 prisoners. They landed at Fremantle, Western Australia 86 days later.
David Sievwright was tried and sentenced to 10 years for robbery at Aberdeen on 14 April 1853. he was 23 at the time of the trial which fits perfectly with the birth I found. He was unmarried with no children. His occupation was gardener. There is also a physical description, round face, light brown hair, hazel eyes, pock marked face, deep scar near left eye and anchors and blue marks on both arms. Fantastic!
Meanwhile back to his family in Scotland. I couldn't find them in the census but tried again using a wildcard S*vright and they turned up on ancestry site in 1841 under Suvewright and in Aberdeen which ties in with the trial: Charles and Jean, William, David age 10 a combmaker, Jean, Margaret, Andrew & Elizabeth. In 1851 it's just David 21 still a comb maker and sister Margaret. Combmaker doesn't tie in with gardener but, apart from this, I think it fits.
Unfortunately I can't tie them in with my Sievwrights but they were from Aberdeenshire too so there is probably an older connection.