As above said by Grim it is obvious that gen sausage lume structure has changed from the beginning.
First sausage dials had deep cavities and lume, manually applied, didn't fill it completely and the contour of the cavities was really rounded and very evident
More modern sausage gen dials maybe had less deep cavities and lume filled it a bit more. We have lume almost flush with the cavities and the cavity contour was less evident and less rounded.
Obviusly last sausage dials, as in PAM 390 and Boutique, seem not to have marked contour and their lume seem flush or even a bit raised, making the reps more accurate than reps of old models.
We can say that gen is now using a lume process more similar to rep, making the reps more accurate than in old models.
I think Boutique's lume is applied in a cavity, I really don't know if PAM 390 has cavity or lume is applied in a flat dial as Grim says. Anyway if PAM 390 lume is applied in a cavity this is completely filled by the lume and contours are not evident. Most likely modern gen lume sausage are not hand made
Thanks Grim form your interesting and instructive comments
ALE