Practice Googling, you must!
http://www.melbourneaudioclub.org.au/gm1998.htm (search page for “Lorpen” - apparently Garth Pennington was the chap behind Lorpen)
http://db.audioasylum.com/mhtml/m.html?forum=speakers&n=5270&highlight=open+baffle+speakers&r=&search_url=/cgi/search.mpl (includes old web address)
https://web.archive.org/web/20011202032109/http://www.chariot.net.au/~pennington/index.htm (using the old web address, there’s a capture in the Internet Archive - hurrah!)
So, which model do you reckon these are?