All the wedge brackets I've seen simply extend the pinion gear so that it drives on an angle. Gear mesh/contact is very small but they seem to work ok. There's no extra gears involved, just extension shafts for the pinion gear. Jim Lipari made quite a few sets of them and seem to be the most common around.
If you ever shoot a large group you'll find some elevation of the camera position makes a big difference to the number of heads you can see. Eventually as you elevate the camera you will run out of fall on the lens, this is where the wedge comes in handy. Goldbeck was shooting some of his military groups (20,000 +) on platforms 200 feet high, that's where a wedge is needed.
Photoeye had some hardback catalogues for a travelling exhibition of Goldbecks work which went through Europe 6 or 7 years ago. It's actually a 136 page book with a great range of his work in it and photos of his setups. They were discounted to about $12 each so I got a few. They may still have them. Great source of info.