Hello Brian,
according to the researches of F. Mattesini ("L'attivitą aerea italo-tedesca nel Mediterraneo. Il contributo del X Fliegerkorps", AMI, Ufficio Storico, Roma, 1995):

- Aghios Georgios sank on a mine dropped by He 111 of 2/KG4, from Gadurrą (Rhodes)

- Embiricos Nicolaos was sunk by Ju88 of III/KG30, based at Gerbini (Sicily)

- Coulouras Xenos was sunk by Ju88 of II/LG1, from Catania (Sicily)

all these sinkings were relevant to attacks performed against ships in open sea, not in harbour.

As far as Kate is concerned, other sources give her as sunk on a mine (probably greek defensive mine, as no mine was laid near Thessaloniki by either Italian submarines/surface ships or airplanes: in the latter case Regia Aeronautica did not have the necessary capabilities); on the other hand, Thessaloniki was raided by 10 Cant Z 1007 of 50. Gruppo BT on Jan., 25th, 1941: I don't know whether Thessaloniki was attacked also on Jan. 28th: it has to be reminded that Regia Aeronautica was used to employ delayed bombs so Kate should have been sunk by this type of bombs, dropped three days before.

Do you know any other detail about the sinking of Kate ?

Thanks in advance

Fabrizio

PS so Sussanna and Kate would be the ships cited in the Hellenic Navy report