Ive got it!
Just came to me, look at the neck penetration into the body, the blue one on Artie's wall is set slightly further into the body than the red version on the left. With the pick guard in the same location on both models, the guard would have a shorter bottom angle piece and the portion above the pickup would be longer.
Look at this picture again, it's now clearly obvious!! There must have been a postional move made on some of the later Ventures II models, mine at B233 has the neck set not as deep, so what the challenge is now is to work out at what number the neck pickup moved aft..!

Here's the one on Ebay right now, B349, has the neck set deeper and shorter angle section on the pickguard below the neck pickup. And here's mine, B233, set not so deep, notice the distance between pickups, it's not much, maybe 3/8" ish;
