Just wanted to say thank you for suggestions/advice on my original post, the London embassy has been speedy in the approval of my visa 😁 (still waiting on Canada)
we thought about changing the dates but decided against it. Thankyou for your detailed info, we may consider 'on arrival'...i think i was just surprised how much was needed that doesnt seem essential for a short stay - its been a good few years since ive visited Thailand. Thanks once again