Re:- the uneven idle speed? -
You might try cleaning the idle jet. I'm not sure where it's located on the Giardiniera carb but on the ordinary 500 it's on the outside of the carb body just above the accelerator linkage connection - it's a large brass screw with a slotted head. When this screw is removed, it can be separated into 2 parts, the screw part is the idle jet holder and the idle jet (it just pulls out of the idle jet holder - you might have to carefully hold it with a pliers in order to separate them) is the smaller part with a cross hole and a tiny hole in it's end, this jet will have a number stamped onto it, something like 45 or maybe 50. Clean this jet carefully, ensuring that the tiny hole in it's end is clear, also clean inside the idle jet holder.
If you do a search on the 500 (Classic) section for 'Idle Jet' you'll find lots of info and pics of the idle jet and idle jet holder.
Re:- the oil leak onto the rear of the exhaust system? -
It might just be a leaking valve (rocker) cover gasket. Try cleaning down this part of the engine again as best you can, then run it and see where the oil leak starts. Usually a new valve cover gasket will cure the problem. Before fitting a new gasket, clean the mating surfaces (i.e. where the gasket seals) on the cylinder head and the valve (rocker) cover, check that the valve cover is not damaged/distorted (use a straight edge/piece of plate glass), then fit the gasket dry (although some people use a light smear of jointing compound/sealant to hold the gasket in place). Iirc, the Giardiniera uses a spring clip (instead of the more usual 2 nuts) to hold the valve cover in place, if this is the case, check that this clip is still capable of clamping the valve cover in place securely, otherwise bend this clip slightly to adequately clamp the cover in place.
You might get more/better responses if you post your questions on the Giardiniera in the 500 (Classic) section - that's where all the 500 experts hang out.
Hth,
Al.
