Spider top cement recomendations

["Brian Carlton" <bcarlton@pacbell.net>]

  I'm replacing the 10 year old (original) top on my 87 Spider. The Alfa
manual says to use a neoprene based contact cement. I have found a couple of
candidates. One is a cement made by Weldwood that is neoprene based but the
label says it's only water resistant. Another made by UPG says it's water
proof but mentions nothing about being neoprene based.
  I would appreciate any recommendations as to what brand has or hasn't
worked for those of you who have done this job before. I'd hate for the glue
to fail...
                        Thanks,
                                Brian