Hawk DLX, 1300 mi., few issues

[Britt]

I just passed 1,300 miles on my Hawk 250 DLX last week and just recently noticed two issues--the first issues I've had with it.

1. I just recently began having symptoms of a problematic ignition switch. Every now and then the bike will die for a fraction of a second while I'm riding it, and I can force it to die by wiggling the key a certain way. When I wiggle the key, the cluster goes dark and then restarts.
2. I've also just recently noticed a little dark oil wetting the cooling fin where the cylinder joins the lower case.

Questions:

1. Does anyone know of a good quality ignition switch that would be a drop-in replacement? Should I just go buy the TT250 set from CSC?
2. If I split the engine and replace the gasket (there is a gasket, right?), is there a big-bore kit that would be worth installing? What is the stock bore diameter (I saw 65.5 listed somewhere, and 67 on the kits. Is one the piston and the other the sleeve, or are these 67mm kits actually bigger than stock?), and while it's apart, is there any machining I could have a shop do that would be recommended?

Thanks!