HR214 SX Rebuild

My HR214 has been a little smoky for the past couple seasons but this summer it's getting progressively worse and now smokes all the time and not just on start up. I checked the plug, it has a lot of carbon build up on it and would probably benefit from replacement. Next I checked the compression and it topped out at 90. This mower starts on first pull just as it's done for 35 years. I replaced the oil with a 30 weight hoping to buy me a couple of months before rebuilding this engine right in the middle of summer, but unfortunately, it made no difference. It's truly time to change out the rings.
What parts would I need outside of the set of rings, a head gasket and valve cover gasket?
Any tutorials available? I do have the shop manual for the mower.
Thank you!
Gail

HR214 SX Rebuild