Some think Petzval/Darlot lenses are cult lenses and they can fetch very high prices for the most desirable models and even the one I've just acquired is worth very considerably more than I paid for it. Thomas Bertilson has a current thread about the issues of using lenses like this "The Real thing or Substitute"
Originally Posted by MacReady
My own take is in the past I've very occasionally used soft focus filters, others swear by specific soft focus lenses like the Dalllmeyer 3B and the Cooke Portrait lenses, others like older Petzval/Darlot lenses. I wouldn'thave paid around £200/$300 to try a lens like the one I bought, I couldn't justify it to myself, but £20 and a chance on it being too far gone or restorable was well worth a go. It may be that I try it and then sell it but there's a possibility of a semi-commercial / educational project using the lens along with Harman Direct Positive paper at some special events.