This listing is for the vintage key seen in the photos.
The tang of this key is for a 5/8 inch lock -it is too short for a 7/8 or 9/8 inch long lock. 

During the years before 1948 the Rock-ola Manufacturing Company used locks from two different companies - Bell Lock of Chicago and EPCO (The Electrical Products Company division of the Eagle Lock Company).  The 5/8 inch locks were used both as coin box locks and wall box locks which attached to metal.  The longer 7/8, 9/8 and 11/8 inch locks were used on door or cabinet locations mounted on wood.

The Rock-ola key codes are largely a mystery to me.  There is a wide variety of one and two digit numbers ranging from 1 to 63 that precede the RO and I believe they mean something unknown to me.   I now believe the 60 and 61 series are post-war and are for the 1422 and that the 62 and 63 series are for the 1426 and/or 1428.  I have not yet seen any of these post war keys that have the Rock-ola name embossed on the reverse side as many of the earlier series keys are.  At one time I thought the numbers following the RO just meant one more key in that series until I realized that 616 and 620 were being used on top  lids and front and back doors on 1938 to 1940 models, or that almost all of the 616 keys - no matter the first number - are identical.  Same goes for the 620 keys. 

Please message me if you can shed any light on this mystery.