Please help to identify my vase with Kingfishers, numbered B122

Please help identify this art pottery maker, one of my favourite pots that has so far eluded identification. Likely to be early 20th century. It is 16 inches tall, moulded with mould join mark still visible, white clay with only the painted number on the base B221. But its beauty is in the quality of the very fine under-glaze decoration definitely by someone of note. Purchased in Derbyshire many years ago. Bretby, Leeds, Dean have all been suggested but nothing convincing to compare it with. Thank you for any suggestions.

It's really nice but I'm afraid I don't know. One of the late 19thC Torquay potteries? Barbotine ware?