Sorry for letting the cat out of the bag, for what it`s worth I won`t be bidding on it.
The Brush generator head on that has two bearings so it could easily be utilized with a roid. It has two slip rings for AC generation and brushes and a commutator ring for starting. I believe the ST1 ran a 12 volt starter setup (my ST2 runs 24 volt).
Air cooled works very well, the flywheel acts as a blower driving cool air through the vanes on the cylinder block. You can get a shroud that allows you to vent the hot air outside.
I would never use the SOM facility with modern electrics. I have rigged a single light bulb to start mine, I then throw the cross over switch once she`s up to speed.
Most of the relays and solenoids can be rewound and the electronics rebuilt. Publishing the manuals would be a great service. Give me a shout if you buy it.
Good luck,
Bob