I had with me a copy of the police report saying my passport had been stolen, a photocopy of my old passport, my new passport which has an issue date of after I arrived in Peru and a letter from HM Passport Office saying "thank you for letting us know your passport has been stolen", all of which was enough to convince the people at the immigration desk that I had a good reason for not having an entry stamp or my immigration card.
They were able to use their computer records to see that my (1)30 day entry permit to Peru had not been overstayed (see above for questions on the use of paper based immigration cards) and so they only fined me $11 for losing the immigration card - a lot less than I had been expecting.
(pro tip: use the left most Immigrating desks at Lima airport, they are much faster as they call over people to the VIP & extra help needed desks when they are free.)
Part of the letter from HMPO stated that the old passport is no longer valid and must not be used if you find it - there would be (serious) questions from immigration people if I did.
As a side note: I would love to have the old passport back - even if i can't use it - there are a lot of stamps in it, all of which bring back happy memories.
Imagine my surprise at being at the cashiers desk at Lima Immigration when one of the managers hurried up to the desk to say that there had been an alert about my passport! Given than my middle name is not "The Jackal" I did wonder what it was about.
Much to my surprise the Lima immigration people knew that my old passport had been stolen and got an alert when the Immigration officer (and cashier) accessed my old entry record (old passport number).
One full explanation of everything (again) and a review of the paperwork later and the manager was happy that I am not some international drug-smuggling super-terrorist trying to sneak my way out of the country by cunningly using their largest airport (cunning, no?) - I am just a traveller who had his passport stolen and I am (trying) to leave the country.
To be fair, I think you could easily sneak out of Peru via Lima airport without too much bother....
Having passed through immigration I wandered towards my gate (having first been robbed of a crazy amount of money for a bottle of water - hurrah for airport "security"), which was past all the gates I was expecting. It was that far past it was actually in the middle of the domestic departures area, an area I suspect is meant to be separate from international departures - the only real difference being if you turn left after "security" (international) or right (domestic). You can walk from one to the other without any restriction once past "security" and then board the plan without any further check of your passport. Security theatre at its finest.
The flight to La Paz managed to leave 10 min late and yet arrive 30 min earlier than expected, which isn't something I will complain about - at 0230 arrival is better than a 0300 arrival.
You are on a plane, flying internationally. Just after takeoff the crew walk through the plane and give everyone Customs & Immigration paperwork - paperwork required by the country you are flying to.
A) Complete this form on the plane, in the 2 hours you have to kill whilst flying?
B) Wait until you are at the Immigration desk to start filling it in, with a plane load of people waiting behind you?
The person in front of me in the queue picked B. If I were the Immigration officer I would have thrown him to the back of the line, but that is because I have spent far too long in airports and have a (un)surprisingly low threshold towards crap airport users.
One short taxi ride to the hotel later (an actual hotel and not a hostel, as I wanted a solo room for the night as I was arriving at silly o'clock and none of the hostels had one available), for which I was charged the normal fare, which is surprising at 3am, and I collapse in to bed at just gone 0300, which is at least an hour earlier than expected.
Jumping from sea level to 4000m after losing most of my acclimatisation from my month in Cusco is a shock to the system - walking up 2 flights of stairs within my backpack was enough to make uncomfortably out of breath. Hurrah for Acetazolamida.