The arc of the guide pin does not have to be an issue if you use two independent connecting rods to the steering knuckles.
The basic principle is that you will have to have the
inner wheels steer more than the
outer wheels, AND the fronts slightly more than the rears.
So: inner front steers the most, outer rear steers the least. outer front and inner rear both are somewhere inbetween...
I could come up with a version in which the rears (both of them) steer more than the fronts, that's easy
but in this configuration it's either both rear wheels steer more, equal amounts or less.
Then again, it may not be pleasing to the eye, but what can you do if that's the way it works?
On another note: it would be interesting to know if we have a "leading" or a "trailing" front axle. All depends on where the steering rack was fitted.
Here is some authentic
Youtube footage, especially interesting at the end (top view of the car without bodywork @Monaco, going through the twisty bits and you can actually see the steering working).
Hope it helps a bit
Jan(edited: corrected a rather obvious mistake)