I bought some Dixie horns off ebay which have been fine, I can find the link later if you want.
They were about £35 from memory and are really good.
Before that, I got some from a different seller. After an afternoon of installing, I took it down the road to test them ... And it was La Chucharacha and played about 5 times quicker than IT should
So there are decent ones on eBay to be had.