Chainsaw Repair

Not sure what you mean by left or right hand start.  I can tell you that the starter cord is on the opposite side from the bar and clutch.  That would be the left side of the saw.  I have all the parts cleaned.  I took a small piece of green scotchbrite and did a little work on the cylinder, mostly on the exhaust side.  Although I can see the scoring all the way up to the top, I can feel it only near the bottom.  And I can feel it less now that I did a little work with the scotchbrite.  I did not do a compression test before I took it apart (I don't have the right adapter for my compression tester), but it sure felt like it had excellent compression.  The piston rings are not stuck.  One question.  I was able to insert the piston back into the cylinder without the help of a ring compressor (which I have).   The end of the cylinder has a taper to the liner, almost like a ramp, which I assume helped me to insert.  So the fact that I was able to do that -- does that mean the ring's fit in the cylinder is too loose?  or am I good to go? 

Oh, and I used my fingernail to remove what looked like clear sylicone all around the mating surfaces of upper and lower crankcase halves.  Should I use something similar to put it back together, or should I use permatex gasket maker of some type?