All shareholders at cryptostocks can already prepare and make an account on Havelock with the same email address you used on cryptostocks.
no no no
I have Havelock account but registered at *different* mail than cryptostock account. What to do in that case?
Register a second account using your other email address at Havelock to receive the shares, and then transfer them to the account you want to manage them. (look for the "xfr" link next to the asset on your accounts page)