I can only find reference to 350 being made, although the split between Sound/non-sound changes between articles.
What's even weirder is that on 21st July, according to this article: https://www.keymodelworld.com/article/key-publishing-accurascale-bradley-manor-limited-edition?utm_campaign=kmw social&utm_content=257744232&utm_medium=social&utm_source=facebook&hss_channel=fbp-129246407114953 there was still 40 left for preorder!
Save speculating on what went wrong (something clearly did), I've responded to Key Publishing, be interesting if we get any more detail...!