I do recommend buying a piston ring installer / spreader , they’re inexpensive on eBay. The solid rings are very brittle and easy to break.
Properly treated they'll go many many yrs without needing service. The key to that is to always return it to it's minimum value when you're done with it. That leaves the spring unloaded so it doesn't lose tension over time. Do that and it'll likely last a lifetime without needing adjustment. One of my wrenches has been with me well past 30yrs. I had it tested a few yrs back and it was still within tolerances. Also... don't rule out the bending beam type wrenches. Although most people look down their noses at 'em, they're just as accurate as any other type.that being said, They need re-calibrated after awhile anyways right? (Right..?)
Those look fine, I wouldn't touch them. When searching for valve lapping compound, try to find a "dual" container that has both coarse and fine compound in it. You start with the coarse and finish with the fine. The coarse does most of the work and the fine just puts a nicer final finish on things .....
Makes sense now. Lol. I used gasoline. Now my garage reeks!Yes, you have to install the springs. I wouldn't use water for the testing. The parts you're dealing with are just raw steel and will rust. Personally, I use kerosene.