If you can't find a trasformer with the same pin positions, you could use one with leads, provided it will fit in the case:
https://cpc.farnell.com/w/c/electro...ers?power-rating=15va|30va&product-range=mcfe
I'm guessing it will be somewhere around 15 to 30VA and likely 12 to 18V output, but you will need to find out the correct valies. If you can't find a transformer with dual 115V primarys, you could use one with a single 230V primary and remove the 115 - 230V selector switch to make it work.
In any case, if you're lucky and haven't messed up a whole bunch of other components, I think it's worth a go if you can do it yourself, or can find someone that won't charge too much to do it for you.
You could also try asking JohnYang, he works for Topping:
https://www.audiosciencereview.com/forum/index.php?members/johnyang1997.5166/