I think this is getting quite confusing.
Many of the above suggestions are both the specification of the original 26 and the later lightweights.
Here is a picture of my original interior which is a later lightweight.
Notice the modern steering column, Nardi wheel, heater controls, headrests on seats, screen mounted mirror, and screen heating vents. None of those were on a 26.
This picture shows the internal roll hoop position, only on lightweights. The tank filler position again only on lightweights, but (I believe) both are on all lightweights.
Here you can see the 16" rims and the Hex nuts that hold them on. On the 26 there were 15" wheels and spinners. Also both cars have two wipes, not three. My previous MKIV though also had only two wipers, so this is no indication of lightweights.
The 15" rims are on the Red Line Car.
My car after being painted and restored. Here you can see the roll hoop better, but also the door pockets and door catches. Note the seats no longer have headrests and the seat belts are 4 point harnesss and no longer inertais. Then look at the inertia belts on the 26 car. They are centrally mounted. I have seen this on other MKI's so no indication again.
Above you can see my dash which has been modified to 60"s style. Below is the dash from the £168,000 car. Totally different and again with the 60's column. Notice no screen vents on the car below and no heater. My car still has the heater with the controls concealed.
I hope that helps a little, but at the end of the day all these modifications are easily possible, and in most cases the cars are altered along the way to peoples tastes.
The Redline car has quick lifts. These were never standard, but are a nice addition if thats what you like.
The most important thing is to buy a good and sorted car. They were not always the most sorted vehicle when leaving the factory, so a good cherished and driven car is often to be desired.
:-)