If your bike is a 67 then I assume you have the binnacle style speedo holder which bolts onto a bracket on top of the fork yolks. Later bikes used a different binnacle which used a chrome ring to hold the binnacle which was then mounted to the fork top nuts.
I've modified the earlier style binnacle for the grey face EMGO speedo by scraping away material from the base. Its quite tricky and you need to keep at it but eventually you can just about get the speedo to fit.
However, even with all the scraping of material from the base, the chrome bezel still sticks out a few mm, unlike the originals which were recessed, so not 100% perfect but ok.
I don't blame you for choosing EMGO replica speedo's, they are cheap enough and are much more robust and accurate.
See below for a modified binnacle and grey faced EMGO speedo on my A65.