I can answer 1, one half of 3, and 5, even though I am new to the art of taxidermy C:
1) Refrigerate or freeze the bird skin if you are not immediately working on it. I once thought I could leave a European starling skin out on the workbench overnight...it was horribly smelly the next morning, and not worth mounting :C
3) Master's Blend is an injection preservative made to prevent shrinkage and decomposition. Here's their information pdf:
http://www.rmi-online.com/information/masters_blend.pdf As far as purchasing just enough to complete one bird, I'm unsure of where to look. Master's Blend is typically sold in 16oz bottles, and runs about $30.00 minus shipping.
In any case (ESPECIALLY when working on waterfowl), injection fluid/preservative is a must. Waterfowl feet are notorious for shrinking, which looks absolutely wretched. Poke around these forums for injection solutions...I've read formalin (formaldehyde) and glycerin works well. No one solution is the best, though Master's is the most recommended.
5) I don't have a tumbler either. I use a plain old trash bag. Stick whatever tumbler-fodder you desire in the bag with the bird, blow it up like a balloon, tie it off, and shake away. About 15 minutes should work.
However, a few tips: - do be sure the bag doesn't have any holes, doesn't get any holes, and is sealed well. A face full of borax and/or sawdust isn't particularly fun!
- make sure there is plenty of air in the bag...it helps fluff the bird up.
- be sure the bird is dry before tumbling (this is a preference of mine). Tumbling a wet bird gets it absolutely coated in grit and powder...a real pain to blow-dry off.
- wear safety glasses when blow-drying the tumbled bird. Borax/sawdust/grit/etc. is HORRID stuff to get in your eyes. In general, just wear goggles all the time.
A few tutorials I find ever invaluable:
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http://www.taxidermy.net/forum/index.php/topic,266936.0.html -
http://www.taxidermy.net/forum/index.php/topic,154914.0.html- and of course, all of the "Wingtips".
Happy mounting!