Don't be put off making your own piston rings. It's fun and you will get a real sense of achievement.
My video below shows the method I used for the very first time. I've used the same method several times since then and always had great success. It takes less than a day to make several rings. Good luck!
Not this engine, but I build a similar (the one in my Avatar picture) which has a 1" piston and is running without any piston rings. Kept the diameter of the cast iron piston 0.01 mm (4 tenths in imperial) smaller than the steel cylinder. With some lubrication it really works well.
I originally built mine with cast iron rings but had great difficulty in getting it to run.
Eventually I replaced the rings with a single Viton T seal with reduced squeeze and it still runs today.