1972 A Body (Demon) Spare Tire Hardware/Install

French demon said
Nobody?

I saw that original and standard Demon tires were 6.45X14", so I plan to install a 175/80R14 on my spare wheel.
This way, I hope that the spare tire will be flush with the trunk floor and that I'll be able to install the cardboard wheel cover.

A 175/80R14 tire has the same outer diameter than my 205/70R14 tires.
So I think that it could be a narrower but compatible "space saver" spare tire as we can find one on all modern cars, no?

What do you think about?

My 72 Demon has a different base-plate for the jack, because of his swiss origin.

But my 71 Duster has the same cardboard (with hole) and also the black metal cup - it is missing on the picture above, it is mounted between the wing-nut and the jack-base - to fix it better.