Well, the obvious answer is to take out the one you already have and measure it. But I know that's not the answer you hoped for but you have already offered potentially conflicting specs so why guess any longer?

If you have a common 3/8x26 axle with no bearing specific aspects then any bike shop can help. If the axle also has site specific seats/shoulders for the bearings then you pretty much have to get an OEM one and kind of measurements won't cut it for true comparisons. Andy (who wonders what hasn't been mentioned yet)