Livre d'Or

Heavier, but there is something to be said for two locks of different types - D and cable. A typical member of the chavousie carries one tool and steals bicycles that can be stolen with that tool.

Dynamo lights are good, but - although I still use a dynamo - the advent of modern LED lights has made battery lights vastly more viable than they were. In particular I think it is worth having two entirely independent rear lights (at least one of which, hence, will not be dynamo driven) because you can't tell when your rear light goes out until some idiot hits you up the stern tubes.

I also like LED battery head-torches, even if I do keep losing them. It is much easier to deal with a mechanical in the dark with a light that's fixed to your head than one fixed to the bicycle (especially if it's a dynamo-fed one that will go out in four minutes).

Gloves are good in the cold and wet - the hands feel the weather more than other bits. Waterproofs - others speak highly of rain legs.

A pump is useful even with no puncture kit - if you get a slow flat you can pump it up and ride home.

You might consider a mirror, some people like them. For all my skepticism on the subject of plastic hats, I was taken with the ingenuity of the "Reevu", a helmet with an ingenious periscope-ish arrangement such that if you looked up at your hat-brim you were looking out the back of your head. Bicycle mounted mirrors generally give problems with vibration.

A cyclecomputer is really nice if you wish to feel smug about getting the miles in. Avoid expensive wireless computers; wired ones are much cheaper and even the low-end ones are very reliable.

A saddle cover (or "plastic bag", as unsophisticates call them) eases life on wet days.