Hammerite smooth in black. Job done.
If you track the car Hammerite will/can melt. I've done it on my old brakes. Gloss engine enamel or VHT paint will be better under those circumstances.
Not saying it doesn't happen, but some peeps do their inlet mani in hammerite, lol - I've done lots of bells/edges in black hammerite and never seen any melt... be interesting to know the melting point.
Hammerite will last a lap or two before melting... I tried high temp silver caliper paint and that lasted 20 mins before blistering and actually setting on fire...
'VHT' branded high temp silver lasts a little longer but ultimately can't take the prolonged heat that track use brings and it still bubbled and turned brown on my car,
Black BBQ paint seems a little more resilient but I much prefer the look of silver tbh, if your not tracking the car though Hammerite will be perfectly fine