don't know if there's a way to courier the passports. i guess this is illegal to courier the passports in and out of india. the same goes with pakistan as well. if you still have a valid visa to visit UK, you can personally go and deliver your passports to CHC London in person on Thursday. once handed over, you can collect them back in person exactly after two weeks on the same day i.e. Thursday. though i am not a CHC London applicant, but i read that you can deliver your passports to CHC London in person but only on Thursdays and that too during a specified time. not sure about the time. i dont think your wife needs to accompany you. for more questions on how to deliver the passports in person and at what time, you can search the website
www.britishexpats.com as majority of members in that website are london office applicants and they know the procedure very well.