[Yosemite Sam]

It would probably be best to remove the column and (at least) take it apart, clean out all of the old hard grease and replace any worn parts.

Be sure to check the "bearing cups" I have seen them worn so badly that they are broken up into tiny pieces and distributed throughout the gear box. I almost never take a steering gear apart without replacing the cups.

Once you put it back together and adjust it, all or almost all the play will be gone.

There is a sponge type looking ring that goes between the steering wheel and the upper bushing, that should help hold the bushing down, if your bushing is very loose you can hit the side of the upper tube just enough to knock it out of round a little, and the bushing will be tighter in the hole. And yes, it does come out the bottom.

Any aftermarket carburetors that I have (bought or sold) come with 2 choke shafts, one style works on our Cubs and the other doesn't.

To the best of my knowledge all of the IH built Cubs (with a factory switch) use the same key. I believe some of the aftermarket switches use the standard INDAK key.
Keys for factory switches can be bought from out sponsors or on ebay.

Trust me when I tell you that you DO NOT want a surface mounted key!!! I can't tell you how many keys I have broken in the ignition switches of my 1X2/3 series tractors. I can't keep from hitting my knee on them and once they are bent, if you continue to use them they WILL break of in the switch. Fortunately for me, I have a friend who is a locksmith and he makes a new ring of keys for me about once a year for very little money.

I personally hook up new to me lights the same way they would have come new. I believe they (on a 1X4/5) get their power from the negative terminal on the charge indicator and are fused before the switch. Consult a wiring diagram to be sure.

Good luck with your project.