Neidermayer antique piano (Konigsberg)

You need to have a qualified piano technician examine the piano to give you any accurate estimate of its value as a musical instrument (as opposed to an antique piece of furniture) because as an instrument it is the condition of what's inside that matters, and you cannot determine that. So altho you say the condition is "excellent", a piano tech might say the condition of the cabinet is excellent but the condition of the instrument is poor, and then give you a long list of things that would need to be done to it to put it in good playing condition.

I'm a piano tech and just from what you've written, I'd say this is a "birdcage action" piano from the end of the 19th century, probably from England or somewhere in Europe. There should be a serial number somewhere on the inside of the piano, usually in the general area of the tuning pins. With that and the manufacturer we can usually look up the year it was made. The medallions are meaningless, as are patent dates. That just means that the company at one time won those awards or got those patents, but the piano itself could be of any year after that.

As musical instruments, these pianos are usually not worth anything because they are difficult to tune and work on, and are mechanically in poor condition. It would usually cost much more to put them in good playing condition than you could ever sell them for. The cabinets are often beautiful. If the cast iron plate and all the rest of the insides of the piano were removed you could make a desk or bookcase or some functional piece of furniture out of it. There are woodworking pros out there who have done this.

But as I said, you should have a qualified technician examine it to say for sure what the condition is. It may at least be playable and tunable, even if not "valuable". You can find a tech in your area on the Piano Technicians Guild website, www.ptg.org There are also early keyboard instrument specialists around. http://www.anneackerkeyboards.com/ is one. You can google on birdcage action piano and get some info (altho without looking at the inside of the piano I can't say for sure it is a birdcage action).

Barb