Ps. 531-29 commanded by Captain Kvikant had destroyed two T-34-85, one ISU-2 and one supply truck full of ammunition, before it was disabled by T-34-85 (?) during the early morning of 15 June 1944. The vehicle was abandoned and destroyed by its crew. Captain Kvikant died two days later from a shrapnel wound to the head (he refused orders to wear a helmet). The gunner, Lance Corporal Haapamäki destroyed IS-2 during the battle of Vuosalmi, 13 July 1944.
Sources: Käkelä: "Suomalaisten rynnäkkötykkien kohtalot", "Panssaridivisioona 1942-1944", Irincheev: "Vyborg 1944",
http://www.kanneljarvi.fi/alasivut/sivu2/Kuuterselk%C3%A4netti.htm