Hello Thomas, and welcome to the forum!
Your 1931 Minor would originally have been fitted with Armstrong friction shock absorbers, incorporating a friction band operating in an internal drum. They are adjusted with a brass screw on the outside. Later variants of these units incorporated a supplementary friction disk and adjustable star spring.
Yours sound like they may be Hartfords or something similar? A photo might help identify them - e-mail to me at
vintageminor@gmail.com if this is a challenge for you.
Having said all that. Hartfords are much better than the originals because the originals are single acting, and not simple to adjust. Your decision to use them depends on whether you are a stickler for originality, whether you have originals, ANC how much you intend to actually drive your car!
Hope this helps,
Ian