Well, the short answer to all this would be to consider the electronic ignition system, part # ID405, sold by
www.centerlinealfa.com. It's a new Bosch dist with a modified advance curve but the specs aren't listed. I think I'll contact Centerline to see if that info is available. There's a discussion on electronic dists
in this thread that you may find helpful as well.
To start the long answer, I don't have the advance specs for the VSZ ignitioned L-jet cars close at hand but I'll do a little digging. I'll wager a guess though that the curve isn't as aggressive as you're hoping for. And the Motronic setup is out of the question with the spark advance and fuel management being controlled by one ECU.
I can't find when the Bosch 045 was last used in the Euro cars but there's no listing for it the 1984 ignition book #PA3469B. What the book does list for 4 cyl cars is no less than 7 different distributors; 4 Bosch, 2 Marelli and one Ducellier. Three have points, three are electronic and one is Motronic. Except for the Motronic dist, all were fitted with vacuum advance diaphrams and the max total advance listed is 33 degrees.