When you had that S-8mm footage telecined, what is the format/CODEC?
The reason that I ask is if it is a heavily-compressed CODEC, you will NOT want to use any format/CODEC, that applies any more compression to the footage.
If it was telecined to DV-AVI (a very good choice), then you should be fine to use the WAB (Work Area Bar) to set the area on the footage, that you wish to make into a sub-Clip, and Share to DV-AVI, naming it appropriately, and designating a appropriate folder, for later Import into a new Project.
If it is heavily compressed, say to MPEG-2, then I would strongly recommend that you use a lossless CODEC, like Lagarith Lossless, or UT Lossless. This ARTICLE will tell you more. Again, you can use the WAB to limit the Export on Share.
One other way is to just Cut (Razor/Scissors Tool, or Ctrl+K) that long Clip, Trim if necessary, and when done, just shuffle the resulting Cut/Trimmed Clips around the Timeline. I would probably pull every other resulting Clip to Video Track 2, and then shuffle them onto Video Track 1, as is required. This negates doing any Share to an intermediate sub-Clip.