Try e-gunparts.com or nutmegsports.com
You might find them at gungrip.com
Such an item would be a custom piece. None are manufactured in that configuration.
for information furnish serial number to: felix@bedians.com
Contacting Colt and getting a letter would be a good start.
You can call Colt or visit their website which has sn data.
barrel or frame
You will have to call Colt to find out. You will have to call Colt to find out.
You could call Colt Archives Services (800) 962-2658 ext. 1343 to find the history of your particular Colt DS .38. May cost some money. Chances are, if it wasn't a special order, it was an after- production acquisition.
You will have to get a letter from Colt to find out.
You will have to call COLT to find out.
Proofhouse.com has Colt sn data.
It would tell the year when it was produced.