Some notes/caveats regarding your questions:
 
Be careful using acronymns.  In common usage, "PVA" in the US usually
refers to polyvinyl alcohol; in the UK, it usually refers to polyvinyl
acetate...two entirely different critters.
 
The "B-72" and similar designations are usually proprietary grades of
a product designating viscosity/molecular weight...such terms are
often used as conversational shorthand amoung people who each know
what the other is referring to.
 
Bedacryl is probably a polybutyl methacrylate polymer.
 
"B-72" is probably an ethly methacrylate copolymer (Paraloid or
Acryloid)
 
_Materials for Conservation: Organic Consolidants, Adhesives and
Coatings_, by C.V. Horie, Butterworths, is a good introduction to
these sorts of materials.
 
A conservator (I am not one) should be consulted regarding the
applicability of any of these materials to your specific needs.
 
 
Gregory Brown
University of Nebraska State Museum
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