Me next! Will you mark the flywheel for next time you set the timing? 

There should be two rings on the piston, unless your cylinder is from a racing bike which may have one ring for less friction. Stock they had two though. The top ring may be a keystone - I'm not a 250 guy so I don't know but it's worth googling if someone here does not chime in. Worth looking very close at both rings to see if one is rectangular and one tapers to thinner on the inside. The idea being the taper makes a keystone ring push into the cylinder when there is compression. If there is a keystone it will be the top ring on the piston.

The springs go underneath the rings, to help minimize piston slap. Some use them, some don't. Generally I figure the engineer who made these things knows more than I did, so if it's part of an OEM ring set I use them.

Yes

Thanks so much!! I was just curious why they were included.