As far as i know Karl the PVL systems do/can come with a ignition curve. This one i don't know truly I bought it on Ebay and it was listed as "Sat on the shelf for years" i do hope it even works it was listed as a Yamaha 350 twin Race Ignition.
So if it work's on the RD350,RZ350 and the Banshee twins no reason it should not work on our Bridgestones.
Regardless i am proceeding forward and when i get it mounted in my #2 Engine I'll run it and observe the ignition timing with a strobe light and adjust accordingly i am for 2m BTDC.
Once its runs , i'll do up some sketches of the rascal and get them posted on this site for future Ref.