Looks like I haven't updated this thread in a while!
The rusty A408 has been our daily-use machine this entire time, only briefly giving up a few loads here and there to the A209.
We did have one issue, two years ago already, where we would occasionally come back expecting the load to be done, only for the machine to be making humming and clicking sounds... hum, click, hum, click, repeatedly. After a little detective work, I discovered that the motor was incredibly stiff to turn. Not seized, but quite close. So if the load was great enough (such as starting the spin drain), the stalled or nearly-stalled motor would overheat and trip the thermal cutout.
With nothing to lose, we sprayed the motor bearings liberally with a penetrating cleaner, turning it by hand for several applications. This freed the motor up quite well, so after letting it thoroughly dry and re-lubricating it, we put the motor back into service and it's been working great ever since. I replaced the motor glides while it was out, opting for old-stock rollers over the newer square sliding blocks, logic being that while functionally comparable for good-condition machines, the rollers would better tolerate the rough surface of the rusty tracks on the machine base of this one.