Does anyone have KOL v3.x ports of the Windows NT Undocumented API's (stuff like NTQuerySystemInformation and NTQueryObject) - in both 32 bit and 64 bit, please?

Is this http://zalil.ru/33450834 what you want?

Thank you - that looks promising. I shall check it soon

But I believe that for 64bit compatibility the functions need different padding - do you know what that would be?

I believe the latest JCL Native stuff will work 32/64

Thanks Thaddy - I found this: http://sourceforge.net/projects/jcl/
Do you know if I need to convert anything for use with KOL?

I spoke too soon - looks like it is in the JEDI API Library: http://sourceforge.net/projects/jedi-apilib/
There is a JwaNative.pas file but there is a lot going on in there! Looks like it won't be a quick conversion :-(

No 64 bit KOL yet. Although some of the code will work objects will NOT work!
(Or I will eat my hat <smile>) JwaNative WILL work!

Isn't KOL (at least, kol.pas) compilable (and work) in Delphi XE2 64 bit compilation?

Yes, compilable - by accident -, but no: not executable. The KOL sourcecode is simply not 64bit compatible.