I recently had the opportunity to replace an original MGB Stow Away Hood still on its original header rail and thought it would be excellent reference for anyone wishing to tackle doing their own hood replacement.
Since this was a Stow Away hood, aka Standard hood, rather than a Folding one, the header has three plugs in the threaded holes where the Folding hood bows would otherwise be attached. Both the Stow Away hoods and Folding hoods were attached to the header in the same manner. Unfortunately, the rest of the hood had already been sliced off before it came to me.
Note that the installation was rather sloppy, compared we have come to expect on modern cars. The hood was fitted to the header by Coventry Hood and were delivered to the factory as pre-assembled units. No additional fitting or adjustment was undertaken at Abingdon. They worked quickly and never looked back. These days we generally take the time to fit the hood with a bit more uniformity.
Coventry Hood is still in business, and up until a few years ago, were still offering OE style hoods pre-installed on new headers, ready to screw to your existing bows. Unfortunately, they no longer do so.
Several details of original construction can be seen in these pictures. Note that the tab for the snap is cut square and unbound. Also the rolled edge on the drip rail edge binding. While making a nice visual detail, this also required an additional step to fabricate and is usually no longer done unless ordering a custom hood at additional cost.