What you describe is what I've always known as roller bearings, and the tapered version of a roller bearing is what I've always known as a needle bearing (each roller is smaller on one end than the other). Sorry if I used the wrong terminology.
Since I've only torn apart glow engines, that explains why I've never seen bearings onthe con rod, just bushings.
They may have bearings on the con rod which doesn't show in the exploded view (the exploded views of glow don't show the bushings either). According to the website the gas ignition version of their engine uses
- for spark ignition: a mixture of 95% petrol (normal or unleaded) and 5% oil (after running in at 6%)
That's a 20:1 mix after break-in. That's a bit higher than the average gas 2-stroke, but the average gas 2-stroke doesn't spin at 17,500 RPM.