WW2 aircraft engineering drawings on CD

Morning all,

Ive come across these gems on ebay and am more than a little curious as to how complete they are and as to what quality.

Has anybody on the forum purchased any of these before?

Although they do other aircraft The Me109 & Spitfire CD really interests me.

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=290348383763&ssPageName=STRK:MEWAX:IT

http://cgi.ebay.co.uk/Spitfire-Mk-I-II-V-IX-XI-XIV-Blueprints-Plans_W0QQitemZ290342223765QQcmdZViewItemQQptZUK_CPV_Aviation_SM?hash=item4399bebf95&_trksid=p3286.c0.m14

Are there any other online sources to purchase engineering drawings of WW2 aircraft?