Randall sheath's were made by Johnson and marked with the Randall Logo.
Good resources for information are these forums and you can use the "search" function at the top of the page to research the Crutchtip 18's.
Other good sources are the reference books:
Randall Made Knives The History of the Man and the Blades by Robert Gaddis
Randall Knives - A Reference Book by Wickersham
Also, the contributors to this forum are very knowledgeable and will probably chime in with other information.
Thanks for finding these forums and hope you will continue to follow them!