Squareback vs round back alternator?

CLBER said
As for the ballast resistor I cross checked your number #2095501 and the one I have in the Valiant book #1889545 and it turns out they have both the same values. Except in my book the resistance isn't shown.
View attachment 1715890478

Thank you. I think you are OK. Maybe attachment method changed.
@halifaxhops may have more complete cross reference.