All the issues featured a cover of a Peanuts character. Here's the cover for issue 10, which came out something like late September or early October 1977.
The way duplicators worked back then was with stencils. These were waxed paper that ink would pass through when they were hit with a typewriter key if you didn't use a ribbon. They didn't cut all the way through the paper, because then the middles of letters like o would have fallen out, but they did. You could see what you were typing because of some black carbon paper behind them (which also gave a hard copy of what you'd typed on some regular paper underneath).
I wanted a cover that was pictorial so it would stand out, but I lacked artistic ability (and indeed still do). I therefore created what I was later to learn would be called ASCII art. The reason I chose Peanuts characters, apart from liking the cartoon strip, was that they were easy to enlarge by drawing a grid over them then enlarging the grid on a separate piece of paper and copying what was in the squares. This meant I could get it up to A4 size (A4 was just coming in as the official paper size in the UK, taking over from foolscap) and put it behind the waxed sheet of the stencil. It was then merely a tedious 30-minute job to plonk a letter over every line I could see. The end results were surprisingly good.
Needless to say, I didn't credit Charles M. Schulz for the original images. I'm not entirely sure that it even entered my head to do so.
The reason I chose issue 10, by the way, was because I only have my brother's copies of Sauce and he gleefully defaced most of the covers. This one only has a squiggle over to the right.