I buy from Trademe.co.nz and only within NZ, I wouldn't even know how to buy from Aussie.
On the issue of oily mess with lens cleaners; ROR will certainly loosen up any oily residue. I use it when I need the extra help, but expect to have to do 3 to 5 applications to get the mess cleared up. That is on a lens that hasn't been cleaned with it before (even a new lens, in my experience). I don't know where the muck comes from, but it doesn't seem to come back to any great degree once thoroughly cleaned. I mostly use breath with microfiber cloths, and a lens pen. ROR if necessary.
The Seneca lens - don't take my word for being a RR, that is just an educated guess. I'd just hate for you to be disappointed if you are expecting something else. I've always meant to try RR's since they seem like neat lenses. I couldn't make out the short focal length, maybe 6 or 8". You should be able to focus either.
ROR is a brand of lens cleaner. Stands for Residual Oil Remover. It does work, but initially often makes things worse until you persist and get all the mess off. They used to make outrageous claims about how improved lens performance, but I believe quit that many years ago. It is often unnecessary, but great when you do need it.
The Bronica lenses have the shutter mechanism built in, so I wouldn't fancy opening one up.