[urq] early style pneumatic diff lock knobs

[Buchholz, Steven]

... I converted my two position lock setup to a three position by simply
buying the newer switch and plumbing another pair of vacuum lines ... the
same knob fit both.

I guess I did do a bit more mods at that point ... that's when I modded the
panel to include two standard VDO gauges and some LEDs to indicate charging
system state ...

Steve B
San José, Kaleefohnia (USA)

> The early cars had a different lock valve (two-way instead of 
> three-way) so
> can't say if the knobs are the same thread.