This was, I believe, DHL UK’s 2nd new 767-300 G-DHLF ferrying to Greensborough after handover, for winglet fitting. After handover at Everett, export aircraft are typically ferried abroad for tax/legal reasons and under normal circumstances it might be expected that G-DHLF would have come to the UK, but Boeing don’t fit winglets to newbuild 767s and the work has been contracted to a company at Greensborough NC.
FWIW, the first DHL UK 767 G-DHLE has been at Greensborough for a couple of weeks and should be ferrying to the UK next week.
Andy