Many thanks for your enormous clue with the IMO number. I've just found the vessel on Equasis. Pity I underestimated the tonnage and build date! Originally, i did think c. 8000 tons, honestly!

She's ex Palau-03 and Commodore (flagship of a Genoa-based ferry company) before that. Apparently, originally built as Prinsessan Christina for Baltic ferry services in 1969 - eek, so much for my powers of deduction. Curiously, in 1981 she was considered for use as an Accommodation Vessel as "Safe Christina" Looks like she has finally reached that particular status at Grimsby!

Best wishes

DAVID