Well thank you all for your help. You have been wonderful, including someone who also pm'ed me.

You're right! It is the bottom of a coffee grinder, now I just have to find the brand. You have no idea how many photos I've googled and perused, both before posting and since! 

If you're interested in the back story - son-in-law gave it to me to sell for him. he was adamant it was part of a Breville Juicer. Since I've previously owned a Breville juicer I knew that wasn't correct. Hence - first lot of googling photos, of all sorts of weird things!

Then yesterday after some of your replies, I emailed off to him - ahh, yes, I remember now, it was part of the coffee machine. More photo googling ensued.

And today, I now know it's a coffee grinder part, and been doing more googling but no luck, and I'll bet my bottom $ he doesn't remember the brand! 

Thanks again to you all for your help - you are all truly amazing people.