Hi Helgard,

 Have you tried here: http://www.assaultgliderproject.org.uk/  there is at least a sideview photo here

 Also a review here http://www.scalesoaring.co.uk/Plans/3Views/BobBanka.html of Bob Banka's 3 view plans. In the review there is horsa Mk1 listed so it may be what you are looking for, there is a link on that page to Bob's site.

(I fly model gliders hence my curiosity)

 

cheers

Bob