A big thank you to all in the group who helped me and the initial advice to get this type of visa.
I received today from the London Embassy my non -immigrant year multiple entry O-A having only posted it on Monday afternoon.
Things that may help other people :
It took me a lot longer to get the documents than I thought so allow plenty of time.
I did post the additional documents to the embassy because I have them handy I appreciate I didn’t need to.
The Thai embassy system was difficult you need somebody who can resize the docs I used the method suggested on the site to resize.
If I can help anybody I will but there are much better people on this site than me.
I agree with posts being closed as it helps you find the relevant information.