Which diacompe hoods do you need? The ubiquitous Diacompe hoods don't fit the grancomp levers....
these (which are that the cane-creek resemble if I am not mistaken...


just fyi. I DO have a set of the gum dia-compe hoods if you are interested but they do not fit very well on grancompe levers. I have a set of red hood that DO fit gran-compe and a set of black chang-star that are also a decent fit for gran-compes... not sure if what levers you have exactly.

Edit: the 70s gran-compe might be different from the royal gran-compe of the 80s that I am thinking about.