anthony - once you have registered on the GRO website - you need to go to the section on the menu down right hand side 'Search the GRO indexes'
On the page which comes up - click 'Birth'
Then input the details you want - you know the year, so just select that year.
Input his name (with surname spelt as Herman).
click 'male'
input reg. dist.
Click Search.
Result should come up.
Select the 'digital copy' option.
Then continue through to the payment screen.
You can do the same for the death of the other baby someone found for you.