**Every** HR214 ive been around loose their elasticity on the oil rings, and suffer some level of bore polishing. I think its because they have thousands of hours on them instead of the hundred you see with briggs / tecumseh.
Just bite the bullet its worth it. Do rings, upper and lower crank seals, and leave the old pan gasket in place and use good RTV to re-seal. The gasket is $9. Way too expensive when good RTV will work. Head gasket can be reused, and valve cover can also use RTV like the engines. These are ABSOLUTLY worth saving. Especially if the mower deck is not plastic.
Forgot to mention run a hone down the cylinder so the new rings seat in.