I can send more detailed photos and information of these antique chairs for sale upon request.
I believe the caning to seats to be the original and is in good condition, as is all the wood.  At some time a few extra cross-headed screws have been added to the chairs, which may be better replaced with reclaimed slot-headed wood screws.  
The chairs all have traces of the original paper labels and are also stamped.
Also know as 'Stuhl nr 25'
I'm sure you'll agree that it's wonderful that these chairs have survived as a set of 4, and should remain that way.
This set of 4 was made by the legendary THONET brothers factory between 1881 - 1915.  Sometimes known as 'peacock' art nouveau Thonets, no. 25 model has fine detailing to the chair back.  The 3 bentwood loops are interlocked, almost invisibly, giving great strength to the structure.
***Please note I will quote precise shipping for these once I know your exact location***
Available exclusivly at ChateauAntiques.com