Reading through some of the older posts I see many are still using the simple 2 piece semi-domes. Whilst these work fine in most applications I find these male & female clamp locators superb 
Flash is very minimal when using these 
There’s no drilled holes that will inevitably become enlarged and misaligned over time, nor will be the need to try and line up nut and bolt.
Two questions…
Who manufactures these?
How much? 
Someone had to ask…
http://www.grpmouldclamp.co.uk/index.html
Prices vary based on the 3 options they supply. They’re not a cheap option, but certainly a better one.
Any pics of these in mold being used?
Mould clamp secured in to the first split.
http://www.homebuiltairplanes.com/forums/attachments/composites/6293d1269622118-carbon-fiber-cowling-grp-mould-clamp-photos-female-m8-flange-024.jpg
Mould clamp bolted in to interfacing clamp, awaiting over laying for the second split
http://www.homebuiltairplanes.com/forums/attachments/composites/6294d1269622118-carbon-fiber-cowling-grp-mould-clamp-photos-female-m8-flange-028.jpg