PMG Issue on GEC. Alsthom Large Machines Limited..

One of our steam Turbine driven Alsthom AC generator's PMG has got damaged. Nearly Six of the magnets have been dislodge from the rotor. Can any body tell me where can i repair my PMG or get an exact replacement.
The specs for the PMG are

270 PMG 101 590A451

Type: 19/40

Rating

Open circuit volts: Not to exceed 200 V

Frequency: 200 Hz

Phases Single

Speed 1500rpm

Over speed 2250rpm

Ceiling Rating 180V 10 Amps

Power Factor .9

Air Gap 1.5mm

The specifications of the Generator on which the PMG is installed.

AC GENERATOR, 3.3KV, 2050KVA, 1640KW, 360A, 0.8PF, 50Hz, 1500RPM, IP:22, INSULATION CLASS: F,

ALTITUDE: 1000 M, HUMIDITY: 0.54, AMBIENT TEMP: 50, IC: 01,

MAX OVERSPEED: 1800RPM, WGHT: 6420 KG,

FRAME: GP500 / 1250 Q,

SPECIFICATION NO: BS5000 - 99, S/N: E-44350601,

Mfg Year. 1990,

Make: GEC. Alsthom Large Machines Limited.