Back in 1983, a booklet called 'Nederlandse Austers' was produced by Herman Dekker and Nico Geldhof about Austers in Dutch service. You can reach Herman Dekker through the details on his website:
webmaster. Herman's website is in Dutch, but you could ask him if he would be willing to dig through his very extensive archive for you.
Edit: scroll down on this page for several Auster photos from his archive (only just found these pages on his site)
http://www.hdekker.info/DIVERSEN/nedFOTO%3bA2.html