I checked the parts catalog on this website
http://www.comancheflyer.com/NS/manuals ... atalog.pdf I searched on cowl flap spring and it took me directly to this parts list in section V for power plant for control quadrant etc. Not where I would have put it so thank goodness ICS made this searchable.
Found Fig 37 item #77 appears to be the cowl flap spring. It shows a couple of part #s. Google gave some hits but I usually call Comanche Gear first and Webco second.
Hope this helps. If you need a photo where this attaches, let me know. Just took some for another twin owner. We went through this at the last annual and it took about 6-8 iterations to make it work well.