I had a quick look and the VHT real red looks about the same colour as I've seen other SB mowers , also the MPN pro red looks the same colour ,you could paint the reel and leave it in the sun for a few hours on a high 30 degree day so the paint is baked on.
I've used a lot of high temp VHT paint and it sprays onto bare metal but I prefer to use an etch primer under the VHT just to stop rust and the paint has something better to grip onto..
Using an etch primer is a good practice because it helps create a strong bond between the metal surface and the paint, improving adhesion and durability.