I checked out DVD's of an old western series called Cimarron City from my library. It was was filmed in the 1958-59 season So far in the episodes I've watched both Rusty Stevens and Frank Bank have appeared in small roles. It turns out Cimarron City was shot at Revue Studios the same studio where LITB was filming at that time. (prior to moving over to Universal) So I guess whenever they neede a kid for a scene on Cimarron City they just ran over to the LITB set and grabbed somebody!