This is a simple 230V / 12V transformer - 20 Watts
Take it to a DIY supermarket and ask an assistant to match it - a higher Wattage is perfectly fine.
The part number is from the Jiaxing Yongfa Electronics Co Ltd - they would want to sell to you in units of 500.
http://yongfaxrz.e.tradeee.com/product_view/50554021/Transformers.html
Anon
March 2015