Aluminium bike frame touchup

[Gixxerman]

My aluminium MTB has started to lose some paint on the bottom on the headstock.
I would like to just touch it up. It doesn't have to be a brilliant job as it is mostly out of sight.
I was going to brush paint it as I don't really want the hassle of spraying.
So what paint to use? Japlac? Hammerite smooth? Enamel?
Will it need a primer? If so, will ordinary car grey cellulose primer be ok?

 

[Cuchilo]

nail varnish

 

[Smokin Joe]

Humbrol model paint. Numerous colours available, cheap, durable and you can mix a couple to get within a whisker of the shade.

 

[raleighnut]

^^^^+2 Both as good, avoid cellulose primer/paint it can react and bubble up.

 

[Mrs M]

Car paint?

 

[mrbikerboy73]

+1 on the Humbrol model paint.