I did some research on OA before my current trip but ended up getting a METV this time,others say the hardest part is getting the medical done in uk , but I understand they will accept one done in los .I plan do that before I ret in april and it is then valid for 3 months ,,applications can be done by post if you contact them first I also read.

non imm OA can be had from london but need docs cert and funds to show in uk bank