Famous for building pianolas (player pianos). Aeolian, London & New Yorkīuilt the Steck & Weber models. It is as yet incomplete we are adding further details and photographs as and when they come to light. We have brought together details and information about the piano brand manufacturers most frequently found in the U.K. Find the pages here for Piano Restoration, Pianos For Sale and Piano Rental enquiries. Challen pianos were being made in London at the Brasted factory, with the “Gors & Kallmann” name on them, and numbers in the 120,000 range, which do not correspond to serial numbers for Gors & Kallmann, or Challen, or Brasted! I’m grateful to Rob Chapman for telling me about a 1936 key-frame label on “Gors & Kallmann” #120,593. I believe it is still possible to buy Gors & Kallmann pianos, but nowadays they are made in the Far East. Know nothing about pianos! The asking price is £75-125. Is gors and kallman a good make for a piano? Looking to buy second hand. Does not look like there is anything rare or special about a Gors & Kallman upright. Some other day, a fellow that works with antiquities offered $6,000 for the piano. How much this piano can value? - posted in Viva Piano: Guys, theres an old piano that just sticks around my grandmas house but its not being used anymore. R Gors And Kallmann Piano Serial Numbers.