have a technician check it first before you get any piano because it may have one single problem that will make the value 0.
it is sort of like a car,.... would you take a car out of the junkyard before you found out if anything about it is going to work? of course not...same with pianos.
since you have it, get your technician to look it over. he may find some things.
mehlin pianos have a good reputation and are restored/rebuilt in some cases. the economy is not favorable toward restoring old pianos except here and there. Now becoming a third world country, the U.S. and all of our really good things are going south. I hope everyone is happy with the hope&change! Enjoy.