Modern Vespa

Does anyone know if Peter Stevens Motorcycles' collapse leaves customers in limbo is effecting Vespa in Australia?

The import / parts / warranty part of the business (PSI) is a separate company and isn't part of the voluntary administration affecting the retail arm.

I'd say business as usual. Possibly no Vespa / Piaggio retail presence of Peter Stevens going forward.

I wonder which brands were not selling?

Maybe Vespa!

Opinion only:
New stores in another state.. plus acquiring another dealership (Melbourne Ducati).. and sales down 3%+ in the industry overall weren't sustainable.

Brands that may not have helped the overall situation are KTM and Zero.
I suspect they'll survive by reversing the errors of the last couple of years.

KTM has serious issues with new nonsold units that's bringing them down. It's sort of like what Piaggio has done in the US where they will stick a new dealership in the same market as one that has been doing well, and start the race to the bottom. KTM figured that they had a waiting list to buy some of their top models, so there was enough demand that they could jack up the prices and make ten times as many of the same bike. If sixteen people want a certain model, and you make ten, the bike is going to hold value. If the company decides to make 90 more bikes so those six people who wanted one can now get one, if they are willing to pay the higher price for a rare model now made in China or India. KTM basically did everything they could to kill off the brand and now they are sitting on more than a year's production of finished motorcycles. Wait until those come up for auction.
While Kawasaki is probably in the best position to acquire KTM and keep it like it was supposed to be, and Yamaha is likely the greatest fit, in terms of understanding the European motorcyclist, a company like Bajaj or CF Moto will likely get their hands on KTM and pump out orange garbage.

^^^ Agreed. It looks like Bajaj is in the lead, but who knows.