The aircraft took off at about 13.10 hrs UTC from Weston (EIWT) for Ireland West Airport Knock (EIKN) to practice flying instrument approaches. The Pilot flew a manual instrument approach in daylight Instrument Meteorological Conditions (IMC) followed by an overshoot. During the overshoot, at about 1,800 ft, the aircraft rolled to the right in excess of 90°. The non-flying Pilot took control and initially attempted to recover. He then decided to continue the roll to the right through 360°. With a high power setting and an inverted nose down attitude, altitude was lost and speed rose rapidly. In the recovery the aircraft was subjected to a gross over-speed with high G loading in avoiding ground contact. The flight returned to EIWT where it landed safely. There were no injuries. The aircraft, as a result of this event, is probably damaged beyond economic repair.