You've got it right. There will be plenty of paddlers around during Fibark. Best bet is probably to hang at the takeout to hook up with someone for shuttle if your doing anything above Salida. If your going downstream you might try and hook up with someone at the festival. If you post another trip planner on here a day or two before you will have more paddling partners than you can keep track of.
Sometimes you can bum rides from raft companies, but this is much more likely to happen if you know one of the guides.
Edit: Added tip:
If you decide to paddle Browns Canyon Fibark weekend I would suggest lining up your crew ahead of time and either boating early or late. Fibark weekend and July 4th weekend are usually the 2 busiest of the summer rafting season, and you will spend all day waiting to jump between commercials and rush through the next rapid if you go mid-day. By either getting on the water prior to 8 am, or after 430-5 you will have a much more enjoyable experience.
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