Jack,
If I interpret your question correctly, you are asking at what point the Classic range (as Morgan calls the - often refered to as Traditional (Trads) by owners and enthusiasts) became more complex?
As we are not talking about the Aero series, we can rule out any of the Morgans you are enquiring about having: ABS, automatic transmission (an option on the Aero), traction control (even the Aero series do not have this) and airbags.
What the newer Classic range will have (and this would seem to be of concern?) are ECUs and complex engine management systems. The basic format of both the car and production methods has remained semi constant (Superform processes are now used for various body panels but this won't effect restoration).
GoMog is a good site for North American owners looking to restore cars and a wealth of information on the Plus 8 in particular.
I'd also suggest looking at our build records as that will give you an idea of how the modern Morgan is constructed - and illustrate how the overall design has changed very little: -
Morgan 4-Seater Build Record .
I hope this helps
