Good Luck. ........
Silja was in the water at that time but they are a ferry company not a cruise line and in the early days probably
did not have the accommodations that their current ships have.
Silja Line Sailings September 1978-May 1979
Vessel(s) . . . . . . . . . . . . . . Ports of call
Wellamo
Bore Star . . . . . . . . . . . . . .Stockholm, Helsinki
Bore I
Svea Corona
Fennia . . . . . . . . . . . . . . . . Stockholm, Turku
You might try digging through some of this, doesn't seem to have a chronological sense to it so probably need to bring your lunch.
http://www.timetableimages.com/maritime/images/archives.htm#M
Or you might even try to contact the site but read this page carefully before you do, he seems a bit crotchety.
http://www.timetableimages.com/maritime/images/email.htm
His name is Björn Larsson
Two that are not necessarily historians but might be able to point you in a helpful direction like some local historical societies since they are pretty close to the North Sea they are Funnel (Erik) lives in Sweden and Christoffer (Christoffer) lives in Finland.
Have fun,
