My advise and the cheapest way is to disassembled the whole bike and send separately. Engine is 1 shipping and the other parts another shipping. I did this before but not UK.
JD Flash copy the front page of your passport , the previous visa page(standby) , 2 photos, print out your 2 way air ticket , print out last 3 months bank statement ( minimum balance should be more than 20k baht), print out your hotel booking at least 45 days because you are applying 60 days visa. Remember to bring along 😷 mask and wear long pants 👖 or else you need to buy mask there and rent long 👖 at the small coffee stall
Remember to wear pants 👖 else they will reject you from entry. Also make sure you copy everything before you go else will be expensive to copy your documents there.