Recommendations on where to buy a 4" narrowed beam here in Australia?
Nowhere if you wish to stay legal and have compliant insurance.
If you aren't fussed about that then have a word with Custom VW, Vintage VW or Das Resto Haus. they'll know where to get them from. Oh, or Tin God
solutions on Facebook. They would know someone as there rolling advert has a narrowed beam for their widened steels business.
Try busted knuckle garage