[T2] distributor rotors

[Robert Mann]

    I suddenly figured I should try the spare rotor which came with my bus
–  made in England, designated R.66 'replacing Bosch 1.234.332.074'.  The
rotor in the distributor is marked Bosch 1.234.332 {molded in} 192 4500
{stamped, bigger characters}.  The spare is like most rotors I've seen.
The genuine Bosch Germany is v different, with a spring-loaded brass slider
which can apparently get centrifuged to touch a spring-steel vertical prong.
    Just to complicate things, the dizzie's serial number reveals it's from
a '62 Beetle.
    The R.66 seems to work fine, tho' I've not tested top speed yet.
     Is the Bosch rotor somehow responsible for centrifugal advance?  Or is
the centrifuging brass slider intended to be a rev limiter?  Top speed is a
disappointing 72 mph downhill  ...  but no misfiring such as I expect from
a rev limiter.  Anyhow is not the VW Typ 1 motor limited by choked-off
breathing?

Robt Mann
'73 1600 dp Devon