Hi I have a very old copper kettle, Simplex Patent No 423201. However it is electric - I bought it at a sale and having looked it up on the net, it looks as if someone has converted it to electric as the only ones I can find are hob ones. Can anyone tell me how much this has detracted from its value, I was going to put it on eBay but don't know if it is worth anything if it has been altered. Thanks in advance for any answers.