Thanks for your patience in waiting for a reply.
We're not part of the department which publishes Hansard: that's the
(relatively newly-formed) department in the House of Commons called
DCCS, which now contains Commons Hansard. Lords Hansard have their own
department, though run on the same technology platform.
Contemporary Hansard is published as HTML on the web, at
http://www.publications.parliament.uk/pa/pahansard.htm - they don't
publish as PDF. If you would like to take up your query with Hansard
directly, you may find their site at
http://www.hansard-westminster.co.uk/
useful.
The Hansard archives, which we are using to produce the site at
http://hansard.millbanksystems.com/, are stored as relatively large
TIFF image files and the XML which we parse. The TIFF files are simply
too large for us to consider hosting them with our present
infrastructure, though this may change in future.