If you have trouble locating LOOK Delta cleats, check wherever the spinning folks get their equipment…maybe at one of those spinning studios. Early in the clipless era, I went with LOOK pedals. At that time LOOK only had the Delta format. So, as my bike collection grew, I continued to put LOOK pedals on each of my bikes so that I would only need one pair of shoes (or, not a separate pair for each bike). Then, years ago…for whatever reason…LOOK decided to stop producing/supporting the Delta format and went to their Keo format. Thankfully, around that same time…as spinning was gaining popularity…it appears the Delta format became the spinners’ format of choice for their clipless systems. Consequently there are now third party manufacturers making them (and Delta format pedals), and I never had to change pedal/cleat formats.
Dan