That old buiding was a sad loss, but the flyover was very necessary. I spent most of my working life in the City and I can remember so many of those pre-flyover mornings when I would get on a number 21 bus at East Street and, after moving a hundred yards in twenty minute, I would get off and and walk to work. That would be the last I saw of the bus, it never overtook me.
The 182 certainly existed. In my ill-spent youth I had more jobs than you could shake a stick at, one of them was as a bus conductor at New Cross Garage. (Believe it or not....On the number 21's! January 1966-June 1967.)The 182 route was the cushiest in the depot and it was the perk of the longest serving members of staff. It was a nice, short little route and hardly picked up any passengers. It didn't start too early and didn't finish too late and the average working day was only about 6 hours. The waiting list to get to crew that route was a mile long. After about thirty years service you may have been lucky enough to end your working days on the 182's.
I don't remember the number 13 though. It definitely didn't run out of New Cross Garage.
Jan, if you mean the 'P' reference being the garage code, which was displayed on the side at the front of the bus, then it was probably out of Peckham garage. 'NX' was New Cross and 'RL' was Rye Lane, that much I remember for certain, and I think 'P' was peckham. (Would make sense.)
I think the two longest routes out of New Cross in my day were the 177, which ran between Embankment and Abbey Wood, (I worked on that route for a very short while and the fare from end to end was 4/6d (22 1/2p.) & the 141, which ran between Forest Hill and Wood Green. I don't know if either of those routes are still operating.
the 177 is still in existence although it only runs from Thamesmead to Peckham now (still quite a long route).
the 141 only goes south as far as London Bridge although it still goes to Wood Green (although its final destination is Palmers Green). It still ran to Forest Hill and Grove Park up until about 1992 although not all
There is a fascinating website (http://www.busesatwork.co.uk/) which gives detailed info on London Bus route history and some info on garages.