Missing marriage in Southampton?

[Christmas bush]

Hi

I hope someone can help with this mystery...
John Clark born 1839 Clunie, Perthshire, Scotland married Mary Green in 1867, Tarrant Hinton, Dorset. He was living in Southampton at the time and was a widower. I've found him living in St Saviours, Southwark, Christchurch in 1861 and he's single.

How can I find who his first wife was without ordering hundreds of certificates from both places? It's thought he was sent to Southampton around 1865.

Any help or advice would be great.

Many thanks

[PaulineJ]

some london parish records are indexed.
What was the name of his father? Occupation for both men?

[Christmas bush]

He was an engineer and his father, John Clark was a master tailor then gamekeeper.

Thanks

[chempat]

How can you be sure that the John Clark in 1861 in Southwark is your John Clark?

Do you know anything else about his family?

There is a John Clerk, 20, Scotland, with father John Clerke, tailor, in Preston in 1861.  Unfortunately he is a tailor not an engineer, but just wondered where they were in 1841 and 1851.

Added:
Ignore that Preston one, found the Father in Scotland in later censuses.

So, do you know anything about why and when he travelled around the country?

[Christmas bush]

Hi yes my friends cousin knows the history but when I looked into helping add documents to the tree, found the marriage information which was a surprise to them. He left Scotland after training to be an engineer then continued in London. He was then sent to help a project in Southampton (Marine) and did such a good job was asked to relocate. I did think that if he married in London his wife could have died in Southampton or her dying after a short marriage spcould have prompted him to take the new job.

I know its a big challenge and thanks for taking time to help.