Sunburst Small Plate, W, M or JM mark - any ideas?

I've had this plate for around 15 years and never known anything about it.  It was bought for next to nothing in an antique shop Devon way and I'd really like to know it the artist can be identified or if its just another mass produced item.

The detail around the rim of the plate is metallic, almost copper in colour whilst the surface is covered tiny 'bubbles'.

I've taken a photo of the marking on the reverse but as it can see this also has some metallic finish.

Thanks

The mark is a bit small to make out. Is it an AA?

I think it’s either a “M” or a “W”…

JM is also possible