Can you help me obtain a drive belt for my Belle Minimix 150 cement mixer which is powered by electric motor?

We a couple of options for a Belle Minimix 150 Drive Belt, listed below: Electric Motor G100 or GX120 uses Drive Belt Part Number 900/99915 Electric Motor GXH50 uses Drive Belt Part Number 900/99926 Belle Minimix Pre 1999 uses Drive Belt Part Number MS01