I also made my first wetsuit out of other people's "cuttings" back in 1965. At the time the neoprene came in sheets (probably about 2 ft by 3 ft I think) and I had one complete sheet of single-skin but that was all. However, nothing daunted, I begged the cuttings left over from other people's efforts and they willingly handed them over because at that time no-one had twigged that you needed to patch wetsuits constantly.
I stuck the bits together crazy-paving fashion until I had a set of pieces big enough to be able to lay out the pattern pieces on them; then duly cut out the sections and glued it all together to make a jacket. (I made the single sheet I had into a pair of Bermuda shorts wet-pants and had to wear woolly socks and kneepads.) I didn't have a zip but and couldn't find a long one to buy, so took apart an old anorak to get the zip, which I glued into place down the front of the jacket. The turn-buckles for the tail were a bit harder but I found some lengths of narrow nylon tape, glued four under the front of the jacket, two either side of the zip, and the remaining four along the end of the tail-piece. So when it was all done up I had 4 neat little bows strategically placed at the front.
It was all reinforced with yellow tape so looked distinctly odd as the tape outlined the crazy-paving. Later I begged some more bits and extended the Bermuda shorts into full-length bottoms and I even made some wetsocks. Knee- and elbow-pads were added even later and that suit lasted me for several years because I always wore a boiler suit over it to protect it and religiously patched it after every outing. It also fitted a darned sight better than the ready-made one I bought to replace it when it finally died.