Here's some background to my original post:
My father bought the Electrall, complete, perhaps 15 or 20 years ago at a local auction ("local" means within 50mi of the farm here in Northern IL). He mounted it on the side of the 450 at some later time and it's been there since. I know it works "mechanically" and I think it works "electrically" (meaning it'll product power at the outlets).
The other "Electrall" accessories, e.g., the baler motor, we do not own.
In later years, I bought an Electrall owner's manual for the unit via Ebay and gave it to my father for a Christmas present.
It's never been used for anything productive to my knowledge, i.e., it's never been used for backup power during an outage.
I took pictures of it a few years ago, mounted on the 450, but I can't find them as-yet. I'll take some more (or find the ones I've got!) and post them here when I can.
I will post, now, some images of an Electrall brochure that I happened upon. I hope I manage to post them correctly; this is my first time here :o)