Is this the HMG 31 or anther Halvorsen 30 Fibreglass Sailing Yacht ??
www.boatsonline.com.au/boats-for-sale/used/sailing-boats/halvorsen-30-fibreglass-sailing-yacht/303132
HMG 4ft draft,not 6ft + different coachouse,but maybe the same hull mould ?
DBY has a HMG on their files,if you Google it .
There is heaps of stuff online. Start here: en.wikipedia.org/wiki/Lars_Halvorsen_Sons
There is also a Facebook page www.facebook.com/groups/849593912199064/