What happened to the SQ 340-300E Celestar? I know Boeing bought them from SQ as part of the deal to sell 777-200ER to SQ.

How many did Boeing end up buying? If I am not mistaken a few were still on order at the time of the Boeing transaction, so they went straight from Airbus to Boeing.

Which airlines ended up buying or leasing those A340 from Boeing?

What were the main reasons for SQ to phase out the A340 in addition to fleet commonality? Performance related or customer satisfaction related?

Why did SQ order A340 in the first place?

Thanks in advance for any information.