Complete Set of 500 vintage marquee letters Pre-1900????

We are in possession of a complete set of approximately 500 very old marquee letters that were rescued from the basement of the Victoria Theater in Dayton Ohio in 1967.

Unlike newer letters (e.g. Adler) that were produced in the 1940’s, these letters are reverse-type cut outs, hand soldered with raised edges around each letter. Each letter has a grooved slot in the back to hold a piece of milk glass to allow for illumination from behind.

Although these were removed from the Victoria Theater, we believe they could be from the Turner Opera House that suffered 2 fires and a flood and was rebuilt in 1919 and reopened at that time under the Victory (Victoria) Theater name. 

Can anyone provide additional information as to the history of this type of marquee letter and specifically to this collection from the Victory Theater or Turner Opera House?

Thank you!