Welcome to merry band of misfits bigbob.+1 with feralmerril.If all the ivory is true ivory it might be worth more than the gun.Hope to see the photos soon.If you will send them as an attachment to me I'll get them posted for you. wingman143 at gmail.com...D*
First question on value is: Are the grips and accessories real ivory or a synthetic? Obviously real ivory is worth far more than a synthetic.
Second question is who assembled the cased set?
If this was done as a special order from Colt, the value skyrockets since genuine Colt factory work brings a premium.
If it was not Colt factory and was done by a custom gunsmith, value will not be as much.
If it was done by a custom gunsmith, WHO that person or company was may add to the value, or maybe not.
Determining if it's Colt factory may be difficult. If the set was special ordered from Colt, a Colt Archive letter would list the custom features, when it was shipped, and who it was shipped to.
If the gun was bought, then sent back to Colt for the work, the Archive letter will not show any custom work, since Archive letters only address the gun as it was when it originally shipped.
If an Archive letter just shows the gun as a standard production gun, the only possible help would be who the gun was shipped to.
As example, if it was shipped to a known custom gunsmith this would give you information for further research.
If there is no useful info on an Archive letter, finding out who did the work may be impossible.
Last, assigning a value to a set like this is always difficult due to the above factors and what the market value for such a set is worth.
Arriving at a valid value may require the services of an expert firearms appraiser.