I think the Aero 8 , S2 exported to the States was broadly similar to the UK S1.
The headlights are from the 'new' VW Beetle and ,confusingly, are swopped over on the Aero.Thus, the N/S VW becomes the O/S on the MORGAN and vice versa.
You can buy pattern parts in the UK but I have found that these do not fit too well.The best are either
Bosch or
Magnetti Marelli both of which which were OEM on the Aero (I think!).
One of the other TM'ers posted a while back that one of the headlamps (not sure if N/S or O/S) was now un-available, but you may be lucky in sourcing one.
If not, despite my comment above, Eurocarparts currently have pattern parts N/S and O/S in stock at £84 each (approx. $104 );see link -
VW HeadlampsThe grey 'rubber' gasket nearly always splits and is very annoying as it lets road dust and dirt into the headlamp.
It is caused by over tightening the headlamp bracket - but it is very difficult to avoid (because it is a rubbish design

).
I am currently on my third set of headlamps.....
Good luck

James