My amateur translation: Invincible victory, Ruler of Czestochowa, long time since caring of us and protecting the future salvation, by penance make us new people of the Heavenly King.
No, the feast day for Częstochowa Icon is March 6. They mean Jabłeczna Icon of Theotokos (also called "Fulfillment of Prophecies"):
I couldn't find a troparion to it.
Also, does anyone know anything about St. Onuphrius monastery in Poland and the miracle working icon of St. Onuphrius, as that is listed along with the miracle-working icon of the Theotokos of Czestochowa icon on the Holy Trinity link that I posted above?
The Monastery was mentioned in the documents for the first time in 1498. It was set up after an Icon of St. Humphrey miraculously floated on the river Bug (monastery is close to the river bank). It was one of the very small amount of faces that never surrendered to the Union of Brest and were Orthodox incessantly. In 1838 brick Monastery buildings were built instead of the previous wooden ones. In 1942 the Germans put fore on the Monastery. Only the main Church remained intact (St. Ignatius of Jabłeczna
also died then). In 1999 it gained stavropigial status. Currently there are 10 Monks.http://www.cerkiew.pl/index.php?id=579
virtual tour: http://www.klasztorjableczna.pl/?id=zdjecia#
The icon floated by the Bug river a few days after St. Humphrey had appeared to the fishermen and said that in that place his name will be venerated. Firstly the chapel was built on a place when the icon was founded, after some time - Monastery. The icon was propably painted in XII-XIII century. Currently it's in the iconostasis.
Jabłeczna Icon of Theotokos was painted in the similar rime and style as St. Humphrey's one. It is also kept in the iconostasis of the main Church.