75MM, HE DUD

Hi, here is CKOALA !
I have seen the lonely HE dud shell with the rounded base. I have red that the Anti aircraft 75 or 3 Inches shells fired above the towns in Great Bitain were made with a rounded base with thin wall to help to break in small iron scraps so as not doing much dammage to the roofs of the buildings underneath.
This is the first time that I can see one of those WW1 AA shells and it would be interesting to get all the measurments to get a good drawing of it as up to now I never went accross one to do the job !
I hope that it had not yet been blown up !!!
I am working on a book about british AA during WW1 and this would be a most welcome help to my work !
Hope for the best...

It is a 75mm Skysweeper projo from the 50's.