I believe this is the thread or maybe this one.

Search is nearly useless when it does work. The fact of the matter is that traveler(s) starting AONE's ex-MRU posted that they had been told by BA/MRU that there was no A availability on their intended travel dates even though it was showing on EF. Iirc A space was made available to them on alternate dates, probably after MRU asked London for it.

I never read any rational explanation about why such a situation existed, including a thread I started on the BA forum. My own guess is that BA's availability is posted to the CRS according to an automatic recipe with less human intervention than one might expect, but they have the ability to insert a check-point in the reservation process on a segment basis that defers to the "real" availability, which on that thin route might be pretty meager.

If it mattered to me personally I would simply fax/email the BA travelshop in MRU and ask them if the situation still exists and what a would-be traveler should do in order to effectively plan travel.

As a further non-sequitor, last summer I thought about booking ex-MRU using IBL Travel rather than the Travelshop, and they promptly booked 3 A seats for me on the date I wanted. (The agents at IBL were uninformed and non-responsive, but I bitc.ed and got the attention of the office manager who seemed to know xONEx very well, and quickly quoted the correct price and was ready to ticket. Only real problem, they wanted wire transfer, although the real show stopper for me was the tedious flights CMB-MRU, misconnecting MRU-LHR, misconnecting LHR-LAX on AA, all of which would have wasted 3 days getting home, where CMB-HKG-LAX arrives almost before leaving.

FWIW, AA and CX have offices in MRU, too:
http://www.teleservices.mu/yellowpag...ing=0000000376

On MRU-JNB, apart from SA there's an additional daily service on Air Mauritius as "backup".

Yes, as noted in these threads, my experience was that A inventory showing on EF was not necessarily bookable by BA-MRU. When I was in Mauritius last week beginning my itinerary, I talked to the agent who set things up for me, and questioned her about the inability of BA-MRU to book flights when EF showed A seat availability. She didn't have an answer but did indicate some asymmetries in the system in that she knew that BA-UK could make bookings for A seats that BA-MRU could not. Whether they were holding them back from being gobbled up by RTW trips originating in MRU is not clear.

Are the flights in fact going out full in first?

There is a little know yield management tool, class availability by point-of-sale. The same booking class has more availability in higher fare POS. It is prevalent in Asia, less so in Europe, Africa or USA. EF shows availability for POS USA.

One way to get around it is to book in higher fare POS, UK in this case, then queue the PNR to lower fare POS for ticketing. The problem is to convince BA UK to book it for you knowning that it will be ticketed in MRU (it will be tough to convince them). If you have access to KVS Availability Tool, you could sometimes see that by switch hosts to different POS.

Would this work: construct the itinerary LHR-MRU-LHR-..... and delete the LHR-MRU segment (or change the date to the end of the RTW) after queueing to MRU?

I don't know the general answer but our MRU-LHR flight was not completely full-- it had one unoccupied F seat. But then the reason we chose that date was that, unlike other mid-October dates, it did show available First seats.

It is where you book the flight that matters. It has nothing to do with your flight origin. Maybe you are thinking about married segments availability which is a totally separate issue.

If you book LHR-MRU-LHR with BA MRU, then the availability would be the same which is probably none. If you book LHR-MRU-LHR with BA LHR, then it should be available. The problem is how to explain to BA LHR that you want to queue it to MRU when you are originating from LHR?? The reason why it is available when booked through BA LHR is yield management correctly presumes better yield through BA LHR office. Also, the whole itinerary needs to be re-queued to Dublin for pricing as you are changing the origin.

Bottom line: yes, it is possible. But you need to be convincing and/or to get a dumb BA agent at LHR office.

I just thought that booking MRU-LHR in UK will raise suspicion about the true intentions immediately, while booking LHR-MRU-LHR will go through easier at the beginning. And then, there are always good reasons for ticketing outside, like: "It's a birthday present for me from my grandma living in Mauritius and she wants to pay in cash over there."

As long as you could convince the BA LHR agent!

Seems to have nothing to do with the intelligence of the agent in London. If I were to ask him to book an rtw beginning LHR-NBO//surface//MRU-LHR-on-around and after he books it and prices it, I simply call up BA/MRU and give them my PNR and ask them to drop the first leg and reprice it, are they really going to say "no, we're going to have to cancel all your reservations and start over"? I'd assume MRU would simply cancel LHR-NBO, tag whatever you want onto the end to make it an rtw, and queue it up for pricing with the rest of the space intact.

I understand the point of your post, but I think it is not possible to include MRU-LHR on an eastbound OWE starting in Europe.

Is is possible to change a continent as part of a reroute ? for eg:

If I have Africa - Asia - US - Europe - Africa can I drop Europe and change it to Africa - Asia - Australia - US - Africa instead at a later date ?

Yes if everything you have done up to that point is consistent with the new routing.