Thanks for great info on 520 restoration!
My dad gave me the Lionel set that contained the 520 engine back in 1956. A little internet research shows the entire set, with the 520 engine, a caboose, an enclosed freight car with "Baby Ruth" written on it, an open top coal car, and O27 track enough to make maybe a 2 meter oval, the whole set cost $19.95, which seems reasonable now, but was about a day's pay in wages for my dad back then. It must have been somewhat of a budget burden to afford this train set.
I used it on and off until 1962 probably, then back into the box it went for the next 50 years. Then one day last week I decided -- for no particular reason, other than it was a rainy day -- to find the box. Voila, there it was, the whole set -- except for missing one of the curved sections of track. I set up a semi-circle as not enough track for the whole loop, and put the 520 on the track, hooked up the transformer. Nothing. Wouldn't go.
But I found the directions in this thread, followed them, and over the weekend got the 520 running almost good as new. As soon as I can find a curved section of 027 track, I'll be back in business!
I always thought as a kid this 520 engine was a good one to have. The best in fact. It's non-compromising. It's not a pretender. Not a show boat. It's what it is. A workhorse. Reliable. And strong. Thanks so much for posting the restoration info.