More out of curiosity, I decided to look at the parts illustration for this engine. I noticed under the Copper Range Docksider illustration, that the Series 1 motor is no longer available. This is something that bothers me about the constant advances and features and changes in products, is that parts become obsolete rather quickly.
So I poked around the parts listings. There is a Series 2 motor available, but it has differing screw mountings requiring a whole new frame to accommodate the different motor. Look here at both part illustrations for #24 and #28.
So Bill, while you're looking for the insulator, I'd also be searching parts dealers to find someone who stocks that Series 1 motor, should you eventually need one, otherwise you'll have an engine that is useless. Or, as these engines are fairly common, you could buy a secondhand one to cob for parts, so long as it has the same motor.
One of the standard things I do when considering a locomotive purchase (if it's not a model I already have) is I check for parts availability. I really do try to streamline engine purchases to ones that use common parts between them. There was one LTI-era steam engine I was considering, but Lionel and also parts dealers no longer had the DC motor in stock for this particular engine, so I passed. If you cannot find the correct DC motor for your locomotive, it's basically junk... or parts for another one.
DC can motors will eventually fail at some point in time, so I try (as much as I can) try to stick to engines where the parts are available. And it seems to be the way things are going these days: It's not just Lionel. Changes in product design along with limited inventory of parts is going to make a lot of products obsolete, regardless of their retail cost. And original low-run production quantities will help insure that there's no profitability for someone to make reproduction parts, as was the case with the postwar and MPC era.
The only saving grace, is if it was a popular model that sold in sufficient quantities, where you can purchase a second used loco to use for parts. Or if the product has continued in current production with the same parts. But even with "low-end" locomotives, the LionChief and LC+ technology use entirely differing components from their earlier counterparts.
Good luck with your engine fix Bill. I'm impressed with how you've come along in the short time you've been posting here. You obviously have some mechanical and modeling abilities, and/or a willingness to dive into projects that a good many who have been in the hobby longer, would never attempt.