Is there an easy way to tell if a previous owner had the hoses replaced with silicon ones?

 

um... they woudl be colored and soft!

 

How soft? Would you be able to collapse the hose between your thumb and index finger?

 

Well most likely replaced lines won't be black.The stock lines will generally be hard and brittle.It should be very obvious if they've been replaced.And redone lines would almost certainly be zip=tied .Thats not to say some people haven't put zip=ties on the stock lines it's just not as likely.Post a pic then we can tell you for certain.