[Spock]

Given that a 98SE upgrade via using some winME is possible, just wondering if any XP files could be used on a win98SE installation to give a benefit. Anyone any knowledge in this area? (I know it's a very different OS, but there might be some updated drivers that could be useful?)

[LLXX]

ME is also related to the 9x systems, that is why it works (a win95 shell also works on 98se for this reason).

XP is more related to 2K and NT4 than 9x, they are very different and it won't work.

[MDGx]

There are few 2000/XP/2003 files that can be used under 9x/ME.
Please see these projects for examples:
http://www.mdgx.com/98-5.htm#KRM9S
http://www.mdgx.com/wmp.htm#98MP10
http://www.mdgx.com/wmp.htm#L3C

Some 9x system updates which include 2000/XP/2003 files are here:
http://www.mdgx.com/add.htm
Examples:
TTF Pack
MSPAINT Graphic Filters

Hope this helps.