Buy a lens board off ebay, they're pretty inexpensive

As for that extra lever... I'm not sure what you're talking about. On the right side you should have a focal plane shutter winder, a focal plane shutter switch, and the shutter release lever--anything else isn't stock.

I think you may be talking about the shutter release button, which can be linked to the front shutter or the focal plane shutter by the selection switch above/behind it.