Hi Cam
It isn't a poly V belt. They are the flat, grooved ones used on modern front loaders.
It is a round section belt. You can get new ones made up to order at pulley and belt suppliers, they have the stuff on a roll, they measure your belt, cut the new stuff to length and join it for you. One brand (at least here in Australia) is Redthane.
The originals are different, they are more of a continuous loop of rope, impregnated with rubber. They are very durable, it is quite likely yours is OK and ready for use. I have a couple of spares, I could post you one if you have trouble getting one locally. Mine are all the original old round section rubberized rope type.
If anyone is looking at getting a door seal remanufactured and want a reasonable one to use as a mould, I have one I could donate for the job. I don't want a new one myself but there seems to be a few folks in the UK chasing them. I have 3 boots, a good original blue one on the only machine I still own (tired looking but no leaks); a good black one I bought new years ago (I was told it was the last one in captivity...) and a used black one which us in basically good shape but has split at the edges, where the front half and back half meet. The splits are small and there is no rubber missing, it has just come apart. I would be happy to give the split one to be used as a mould for getting new ones created, if that is any use to anyone. You could try to repair it but I wouldn't trust that old rubber...
I am keeping the good ones.
Chris.