>I tried doing a search for the post here which mentioned that these were apparently a deliberate attempt by Webster to differentiate American English from British English.

I've tracked down some of the discussion you mentioned (I think) but I suspect that it is spread over a few threads. One started under the heading "decimate"
http://wordsmith.org/board/showthreaded.pl?Cat=&Board=miscellany&Number=1392&page=&view=&sb=&vc=1#Post1392
in Miscellany back in May and included this link:
http://www.uta.fi/FAST/US1/P1/ahonen.html

There is another (more trivial?) thread at:
http://wordsmith.org/board/showflat.pl?Cat=&Board=words&Number=1799&page=&view=&sb=&vc=1
for anyone who is starting to feel that they have "lost the plot"!