Will,
a while ago Raymond posted answers to similar questions like yours:
viewtopic.php?f=14&t=2402&hilit=lp+giovanni+ash+congasAlso here are some bits of interesting information, especially by Raymond and Jorge Ginorio:
viewtopic.php?f=14&t=2404&hilit=lp+giovanni+ash+congasSo, as far as I get it, in 1996 LP introduced what we know as the Giovanni wood conga series today. And the wood was North American Oak with the first models, which they later changed into ash for some reason. Funnily enough, they weren't even called Giovanni Series because Giovanni was no endorser back then. Anyway, I cannot imagine they used solid staves at any time.
Hope this helps, I am a bit late in replying, I have to admit
All the best to you my friend! Have a blessed and fulfilled new year!
Mike