SFA and SFB are the oldest in SQC's a/c stable. They should be close to 16 years now. A vintage by SQ's standard. Not sure whether SQC follows the parents' standard in fleet renewal.
The 744s from SIA were planned way back in 06, but SQC backed out. Some of the rumuors then were drop in demand then and the lack of nose cargo doors in the converted freighters.
ith the A380s coming online, will SQ be excess a few 777's, and might they migrate to SQC?
Currently, Boeing has no freighter conversion kits for the B777. I don't think they will make one anytime soon as it will cannibalize their factory made B777Fs.