1855 Paris Exposition medal for sale

I picked up this medal thing on a whim a while ago, but I don't have any flips big enough for it, and it doesn't fit in my collection pages. It's pretty big, it's 46mm across and has a really unusual design on the reverse. The item is the one in the picture on this page because I was the one who entered it into the catalogue.

I'll do it for NZ$25 + $2.50 postage

https://en.numista.com/catalogue/pieces71795.html

They don't come up for sale very often, and the ones I have seen have been really expensive. This one sold for US$45 (NZ$70)

http://www.worthpoint.com/worthopedia/exposition-universelle-paris-1855-153488194

As you can see, mine is in better condition than this one, which is all nicked and knocked about around the rim.

That's an interesting reverse, what does it mean?

I'm not positive, but I think these things were made to be set into pianos, the reverse is just a pattern so they can put the adhesive in to stick it into the pianos. But I could be talking complete rubbish so pay no attention.

I've seen a few of them and all have variations on the circular patterns.

Nobody want it?

Unusual design, but not my cup of tea.