This Colt .45-22 Conversion Unit Kit was shipped to John J. Tobler in Union City, New Jersey on July 30th, 1940. This Conversion unit was built for the Service Model Ace to allow it to be converted to a .45ACP Pistol.
The finish is blue and is noted that it was Furnished with an adjustable rear sight.
This particular Conversion Unit was part of the Lowell E. Pauli collection for some time. Mr. Pauli was the Historian for the Colt Collectors Association for 20 years.
Note that this Conversion Unit is consecutive to that of U-99 which can be seen here.