Would this be the same for a multi non immigrant O visa based on marriage to a Thai?

I'm not sure if you can do it the opposite way...a visa for Ireland and visit the UK....

No a she had a UK visa there is an agreement between UK and Ireland that enables the same visa to be used for certain nationalities...Thailand is one of the nationalities :-)

I took my Thai wife to the Republic of Ireland when she visited the UK last August....

I took mine to the embassy with me + a copy..just in case

Non-Immigrant Type O

Birth Certificate (applicant's child)A copy of marriage certificate and a copy of Thai passport or a copy of Thai ID card (if married to Thai national)A copy of marriage certificate,a copy of Thai passport/a copy of Thai ID of spouse and (3 months bank statement showing monthly income of more than £1,400 annually.)An official recommendation letter from organization perform voluntary job in Thailand (for volunteer job)Pension statement if the applicant is a pension earner.

They didn't contact the 2 names I used in April 2016

I needed finacials when applying through Liverpool Consulate who passed it on to London July 2016

Is it still true that if you are 65 or over you only have to show state pension statement for a multi O in the UK Thai Embassy?

I did a border bounce today at Nong Khai/Lao my multi o expires 1st June 2017 so got the last 90 days..no problems :-)