To me it is a male bathyphilus now; it has an outstanding yellow belly and without any spinous prolongation from the first dorsal fin that Tonga FW has in males. It seems a variant from Tanna Island not Efate Island of Vanuatu.
So why would they say the source is Tongan? Vanuatu fish don't flow thru Tongan exporters. Maybe Jim will chime in here, he's seen tons of them via the Tongan station he worked at