For what it is worth it looks to me like a sheet metal (or leather ) workers clamp. Do the jaws lock shut when the handles are closed as there appears to be a slight "cam" at the handle end.
I think Grandpa is correct and it is in fact a Chalmers. The following link shows the exhaust side of a pre 1918 Chalmers engine which appears to match the engine in question.
http://forums.aaca.org/topic/83358-please-help-identify-a-chalmers/?tab=comments#comment-353242
So the reason for the taillight switch being on the rear of the vehicle was to stop people turning off the rear taillight when being chased by the police. I was always told it was a safety issue in that you had to physically get out of the vehicle and turn it on and at the same time you would check that it was actually working. Guess I was misinformed.
Just a guess could it be a Rutenber engine? Also on the rear tub there is a bracket (possibly for a spare tyre) which is distinctive and may help in the identification of the vehicle.
As an Australian I totally support the actions of the Australian Border Force in enforcing the removal of asbestos from vehicles imported into Australia. Should have been happening since 2003 but better late then never.
The unidentified car has unusual headlights in that there is a smaller light under the main one and this may help identify it. I know these lights have been subject of a previous discussion on this forum.
Attached is a photo of a Studebaker rear end which shows the rear universal with its cover/sleeve removed. lf you remove this cover you should be able to bolt up the front universal/hub and then slide the rear one sideways into its slot and replace the sleeve. Hopefully the sleeve is not too tight and it will come off without too much trouble.
I agree with you Tinindian over tightening to the next slot is not the way to go. I generally rub the face of the nut on a flat file and in some cases where the nut is hardened I might use fine emery tape or paper. Generally the amount of material to be removed is minimal.
If in fact you have a Series 18 vehicle as stated the crankcase shown will not fit. In this series the rear engine mounts were modified by the addition of a large circular casting bolted to the crankcase. The crankcase shown would fit a Series 17 or earlier.
I assume you are referring to the dark coloured radiator surround and not the actual radiator on Dosmo's photo wheras Leif's photo shows it as brass. How do you know it is not made of brass?