Thanks again Himeno.

Yes you did warn me about the HEL-DXB flight but I am really struggling to get back to Middle East to end the trip. HEL-DUS-AUH you suggested costs an extra segment. Chances are I will finish in HEL and throw away the last segment. Ideally I'd like to get back to London or close but that adds hundreds to the taxes.

Re. "The online tool will only show flights which have the needed booking class available. If D on LA801/5OCT is not available, the tool with either offer a downgrade to L, or nothing. Try a different date."

OK - I didn't realise that each codesharing airline has its own quota and you are right LA801/5OCT is not available but QF322 is. However if I check on flightstats for LA801/6OCT it shows D availability of 4 but it still doesn't come up on the planner:
http://www.flightstats.com/go/Flight...areClassCodes=


(LA) Lan Airlines 801
Departs:11:50 PMSCL Arturo Merino Benitez Airport
Arrives:4:00 AMAKL Auckland International Airport
Equip:340

0.15 out of 5
Available Seats:
First: n/a Business: 9 (at least) Coach: 9 (at least) Other: n/a
Fare Classes: J/4 D/4 I/9 Y/9 B/9 H/9 K/9 M/9 L/0 V/0 S/0 N/0 Q/0 O/0 X/0