I've just checked mine, and it's just a V, with no S.
I can't find the bearing details, and it's not easy to get into measure them without dismantling things.

However, the ML10 page on lathes.co.uk indicates there's not actually any difference in the taper bearing headstocks between the different versions-

Later machines, produced from January 18th, 1978, (from machine V137261) were
fitted with grease-lubricated roller-bearing headstocks that, although provided
by the factory with the same speed range as the earlier machine, can easily and
safely be adapted by their owners to run as fast as the later "Speed 10" version
(see below for details).
On the 4th of May 1979 a modified "two-speed" countershaft unit was introduced
that carried an eccentrically-mounted top shaft with a double-step V-belt pulley
drive from the motor; this arrangement doubled the number of speeds to twelve
(of which ten were officially sanctioned as safe to use) with a range from 48 to
2000 r.p.m. This new model, the "Speed 10", was identified by the prefix "VS"
and the first down the production line carried the Serial Number VS143202M