Access the Internet and type in your search engine, "Koken barber chair parts." You will find listings for individuals and businesses selling or looking to buy original Koken barber chair parts. Auction sites like "eBay" or antique sellers like "Antique Mercantile" may offer entire chairs for sale or just the parts. Still other websites or blogs like "Antique Barber Chairs" devoted solely to barber chairs may have discussion groups where members have posted parts for sale.
Visit antique stores. Sometimes the owner will be able to provide information about where to get unique items. Many antique stores have bulletin boards and these too can be a place to look for leads on your original Koken barber chair parts. Some antique stores cater to specialty niches like antique barber chairs and other related items. Don't forget to search the multitude of online antique stores as well.
Post an advertisement in your local newspaper or trade publication to try and locate parts for your barber chair. Just put your information in the "Wanted" section and be sure to be specific about what it is you're looking to find. It can also be helpful to indicate if you're willing to make a trade as well.
Review the advertisements and classifieds in magazines geared towards barbers like "Barbers Only Magazine" or "Barber Style." Read articles about Koken barber chairs and contact the author using his listed contact information. If you don't find any leads, consider running your own ad in the classified section of the magazine.