Was there ever any set pattern for how to name models? Some of them *almost* line up across the series but it's always made me wonder why they weren't more straightforward:

420 - - - 4000
450 - 610 - 330 - 4001
460 - 620 - 360 - 4003/4005
- 650 - 380 - 4004
- 660 - 381 - 4002?

with a middle pickup adding +10, a trem adding +5 and a converter adding +6

Forgetting the 70s and 80s models (because everything was messed up during that 20 years for all of us :P ), and allowing the 5000s for the "others" the 310, 325, 300 series above 381 and the 900-1000 series are all "odd men out." The 390 with pickups is a 391 and then a 392 with a trem? wouldn't it be 395 for the trem? Madness, MADNESS I SAY! ;)

Maybe it's just me but I would have made a 330 = 630 = 430 = 4030, etc..... And why not fill things in with a single pickup 300 series (maybe there was, I've never seen it)?