I'm not Jim, but to answer your question...

There were at least 3 Reno arches. The one in Jim's postcard was erected in 1926. (There were smaller wooden arches that predate the steel structure, too.)

The next arch was erected in 1964, with neon, etc.

The current (3rd) arch was erected in the 1980's.

BYW, the 1926 steel arch was found, brought out of storage and erected on a side street south of the Truckee river near the (now closed) Holiday Hotel, beside the automobile museum.