There are at least 27 models of mechanisms/mechanics and many
variations, plus many variations and styles of casework on these
instruments.  On the larger models you could even choose what stops
you wanted, rather like the pipe organs.  To give a valuation I would
need to see a photo in good light, also a list of the stops, reading
from the left.

What condition is the case in, and details of "Is it in original
condition, or has it been 'got at' in any way?  Has any restoration
included the main bellows, pouches, valves etc., or just a retube?

"How many rolls are included?  How long is an elastic band?"

I have seen them sold in UK from GBP 7,000 ($10,500) down to GBP 300
($450) in the last 10 years.  It really is down to how much the next
person will pay, and how large their front door is.

Let me know if I can help further,

sincerely,
Kevin McElhone, Northampton, England.