Exactly as I understood the situation.
As I found it the production of the later I chassis left much to be desired and was a stark contrast to S chassis production.
I say this because there was a full set of drawings for the S. Properly drawn with full material specs and every engineering detail. All were notated as drawn by SG.
There was also some continuity in production.
The Alfa I chassis drawings were never complete, sparse in detail and dimensions and most fabrication was done from detail contained in a red hardback notebook at the fabrication shop. This had been passed down from the S chassis fabricator.
Sporadic production cannot have helped either as lack of continuity meant that critical dimensions and details may well have been missed. Development would also suffer, naturally.
Couple all this with a complete disinterest at the fabrication shop who really did have better and profitable things to do, and no wonder that things went wrong.