Although you might not notice it, the style is a little different from his later strips. It's a little bit simpler, with less Zip-a-Tone (the rub-down adhesive-backed film that adds dots to an area to give it a tone) and solid black inked areas. But the style is still effective and compliments the humor.
For comparison, here's one from June 1974 (below). It's just a little more polished.