This is an important bowl to identify in my opinion.
If it does turn out to be a British piece, then it shows they were producing iridescent glass with applied coloured trails. I haven't come across anything like this and I am trying to identify two other applied trailed pieces with an iridescent surface - one on the body only (applied trails not iridised), the other also has different coloured trails to the body (but body is coloured) but the vase is iridised all over.
The trails on my two are not the same as this one - but on one of mine they do match the shape of trails shown as being from Stevens and Williams.
The trails on yours are difficult to see but appear very similar to the two coloured peacock eye trails on Richardson and Stuart pieces.
I have been wracking my brains as to where I've seen this bowl before, and I believe (difficult to tell as from a photograph) that it appeared in Manley's Victorian Glass as number 284 ( the later version of Manley I think)
Albglass if you are still on the board, would it be possible to have a clear side on photograph of this bowl against white to show the colours and the trails please? Thank you

Could someone check for me and see what Manley says about it please?
Thanks so much
m