May have just found a replacement, £10 including postage. Programmable so it will be 450mA @ 19W. What do we reckon?
https://www.tci.it/en/products/led-drivers/8367/dc-mini-jolly-dali-bi/
https://www.tci.it/en/products/led-drivers/8367/dc-mini-jolly-dali-bi/