Still banging my head on the wall about this one... it occured to me that the linkage assembly has several solutions, and indeed Geogebra gives me 3 potential set of angles, but only one is plausible according to existing photos of the set.
I assembled the car using Geogebra solution angles, the linkage works perfectly but... there are heavy collisions!
I assembled the car using Geogebra solution angles, the linkage works perfectly but... there are heavy collisions!