It is very difficult to accurately price a rather rare firearm- there are simply not enough sales to compare it against. Your gun was likely a product of the S&W Custom shop, and should be appraised by an actual firearms appraiser. S&W customer service can help you locate one. Value is likely at least $2000 US, and possibly higher. And thank you for enough of a description of your gun to get us in the ballpark. Usually it is "What is my Winchester worth?"
In July 2015 an unfired specimen in bright nickel with original box, papers, accessories sold on Gunbroker for $3,250.
100-400 USD
If the gun appears unfired or factory fired only and does include the factory colt box and paperwork, it would typically be worth somewhere between $4500-$5000 in mint condition. I have a consecutive numbered set of Boa's myself (one 4" and one 6") that are pristine and only factory fired and they are only going to continue to increase in value.
In the 400-500 range if NIB. If just the revolver deduct 50-75.
$1100 as new and $725 excellent (Standard Catalog of S & W, 2006).
Depends on exactly what you have. 500 to multiple thousands or more, again, depending on EXACTLY what you have.
Fired- hard unfired-soft
Unfired pottery. Usually dry unfired things but it could be leather hard and not yet dry as well.
I would guess original and unfired about $900 plus or minus
If original and correct, it would be a museum quality piece worth over $20,000. Guns like this dont just show up without any information - which leads me to believe something isn't quite correct. Can you send digital pictures? sales@countrygunsmith.net
You don't
Many people mistake a loose cylinder for the normal cylinder play while the gun is in the unfired position with the hammer at rest, the trigger forward. With the gun in the fired position, the hammer having hit the firing pin and the trigger pulled back, the cylinder should be somewhat tighter and not have as much play. This is normal, to have more play in the unfired position and should not be corrected. For a true "loose cylinder" with too much play or movement, you would have to replace the cylinder and yoke assembly and then fit the revolver with a new hand to time the action properly. This requires skill and is not an amateur undertaking.