Sorry, I'd love to be in a position to help you out, but I do not possess such a device.
If they're difficult to source then you could argue for buying something that's as similar as possible (same power rating, similar dimensions, similar way of working (solid state/valve etc)) and see what we think? I mean we're obviously going to call shenanigans if you replace your broken MB500 with some 2000W behemoth. But we're fair - try us!