According to Michael Palmer's rather nice book "Morgan 4/4 - first 75 years":

"The door aperture was increased by 2in (51mm) in late 1997, leading to these models becoming known as 'long door' cars. Part of the redesign was due to the fitment, or possible fitment of airbags...dashboard redesigned...demisting vents lost...equipped with heated windscreen...under scuttle rollbar...antisubmaring seats...side impact door bars"

So the long doors coincided with a raft of other safety changes. Apparently fitted with airbags, the trad tested by MIRA "produced the lowest rate of injury of any car tested".

Interesting eh? And yes they are still around, it is the current design. The overall length of the car was unchanged at 153 inches.

Nigel