Here's a link about Rege Cordic and his radio show; naming the 77/54, the "flying fraction," and also if you page down you will see that he used a Pittsburgh Railways transfer to advertise his radio program. Obviously printed some time in the mid-50's after the Millvale & Etna routes were converted. http://cordic-and-co.com/bios_etc/JohnMehnoTribute.htm