I somehow managed to wheel the Surly LHT out of Brixton cycles with a much better seat post than the one it came with (saddle kept slipping and tilting) It was horribly expensive for a seat post, though...but I need a seatpost I can adjust with a multi-tool while on tour and this one is supposed to be very good.
I also got new brake blocks. The Tektro brake blocks it came with have always been total rubbish; they required me to squeeze the brakes hard to gain any kind of stopping power and they'd picked up heaps of grit and bits of aluminium
It's a good job none of my loaded touring last year included going down big hills! The new ones are much better; he replaced the blocks with kind that take inserts because the old ones didn't. That was also rather expensive, but allegedly they are 'really good' brake blocks. I forgot the name; they might be Aztecs.
(I was cheerfully letting them do the fitting, cos the bike has free labour for a year after buying and that's coming to an end. And I hate fettling anyway.
I hope you have noticed that my winter boots are doing a fab job of keeping the cold weather away!