Adam,
I'm one of the many viewers. I passed it along to a friend of mine who's having optical issues with his 16" but he wasn't interested in swapping mirrors. I have an 18" scope with a Galaxy Optics mirror so I'm not interested for myself. Just a few suggestions......
You could also try listing on Australian Astronomy Buy and Sell
https://www.astrobuysell.com/au/
SDM telescopes doesn't build anything under 20 inches now. Dob Stuff in the USA sell dob kits.
http://www.dobstuff.com/ It might be more saleable if you make it into a working telescope. All large scopes are hard to move. There was a 20" scope on these classifieds for best part of a year.
It's a very specialised item in a small market. You might just have to be patient.
If you're prepared to ship internationally, the USA is a much bigger market.
Various large forums have online market places.
Good luck
Joe