No two ring gaps should be at the same angle, and no gap should be at right angles to the piston pin (your 12:00 and 6:00). The actual angles are not important, you can have gaps aligned with the piston pins. I would st the top ring at around 2:00, scraper ring around 10:00, and the two straight oil rings at 5:00 and 8:00. with the spacer corrugated ring around 3:00 or 9:00. No rhyme or reason really, but it avoids gap alignment and the 6:00 and 12:00 positions. I've seen solid oil rings that look flat and some with slight bevels. The bevels if there should both scrape towards the corrugated ring, ie "sharp" edges towards the centre.
