The name "Lionel Jr." was coined to identify the trains that ultimately became known as Lionel 027.
While the locomotive is well scratched, the photos of the mechanism make it look like the motor itself is in good condition, and probably only needs a cleaning and lubrication.
I don't see the rear truck or drawbar in the picture. It could be I missed them, or they might be laying in the bottom of a box. If not, these parts should be inexpensive.
I am not certain whether this applied to this particular engine, but on some of the Lionel Jr locos, the siderods are actually held to the wheels by a protrusion that is rolled (staked), and are not removeable. If this is the case for this loco, be carefull not to break them off.
In my experience, most folks would rather have their original family heirloom fixed (scratches and all) as opposed to getting a replacement, even when the replacement is the exact same model. There is something about running uncle Charlie's or Grampa's train that is lost with a replacement.
When I have told people that the repair bill would exceed the value of the train, I have never had someone decline the repair.
I would suggest substituting a newer transformer, with a non-metalic case and built-in circuit breaker. Put the old one on a shelf or in a box.
