I have both a Weston Master model 715 and Master II, and the emulsion speed dial works the same on my two meters. However you have to be sharp-eyed because some samples (UK?) are one mark different than mine.
In this thread, we explored the difference.
The bottom line for me, I set my Weston's at 160 to equate to EI 250 which is the speed I prefer to shoot ISO 400 films.
A bit convoluted, but you can see that you probably should not set the meter at 400