Hi Matthew,
I have a 1985 4/4 4 seater which has done nearly 100,000 miles and runs very well. To stop your bouncing try Koni adjustable shocks on the lowest setting all round, they realy help keep the wheels on the ground when cornering. You may have to fit an aftermarket fixing kit to the rear if you have the leverarm shocks still fitted.
Regarding the gear stick shake check the rear gearbox rubber mount as they are known to pull apart with age if they get covered in gear oil.
With regards to the choke, it should be an electrical one. Mine had the same problem but was fixed with a new choke diafram from my local weber shop.
I hope this helps, have fun.
David ( Oldbill )
