Re F-27 regos.
If memory serves me correctly , the F-27's were all to be TF* , however , the sequence was broken when it was found that TFO had already been used on a C402? with Thunderbird Aviation. TFM was the first "QC" ( Quick Change ) and stayed as such and the remaining deliveries were given TQ regos.
TAA used to operate a weekly DC9 CNS-POM-HIR v.v.. Henry Blackman ( AKA Larry,AKA Greasy,AKA Shaggs ) did a supernumerary ride once but declared the thing too bloody fast and maintained his preferred mode to HIR as the DC3 service Rabaul-Buka-Kieta-Munda-Yandina-Honiara ( once landing on the HIR golf course when Henderson Field suddenly closed due WX ).