Hacker Hunter rear grille
 

I recently bought my first ever vintage radio: a lovely Hacker Hunter. I'd heard that the plastic grille/vent on the back is well known for falling off and going missing. Sure enough, my unit was missing it.

I found the following product on Amazon which fits almost perfectly:
https://www.amazon.co.uk/Mini-Vent-G.../dp/B00JNVW7GM

It's white so I painted it black like the original (sorry for the rubbish photo). It looks a bit different to the original but I think it does the job so hopefully this might be of use to somebody out there.