I would think they're the same, I would think the optical block is identical, from the back, the first ring holds the optics to the helicoid/mount.
As a side note, I just repaired my 5cm/1.8 and think it would be useful to post what I found out, a while ago, I tried to unscrew a LTM to M mount adapter off the lens, and it was a bit stubborn to come off, I ended up using more force than I expected on the focus ring and it became hard to focus, I assumed that I had bent the guide rail that keeps the optics from spinning when you turn the focus ring, I was sort of right, this lens has a different construction than most lenses I've worked on, anyways, there is a rail/tab, and I did bend it, but it only stops the helicoid from turning too far and unscrewing the mount/helicoid off the rest of the helicoid/body & optics, it is definitely a weak point, I advise not using the focus ring to tighten/loosen the lens off the camera/adapter, the filter ring may be a better option(use caution, I am not 100% sure it's robust, but it does seem better than the small brass tab/rail that I bent.