"Cushion-case" models are (in my experience) in the -603x realm and are somewhat smaller then these larger -6002 and -602x styles, like this -6030 (one of the earliest of the -603x's, with a "water proof" caseback notation):
The -601x styles and -70xx styles have smaller, more "dressy" cases, such as this -6011:
If you are looking for more angled Bell-Matic cases, look no further than the -604x, -6050, or -608x case styles. These uniformly come with an integrated bracelet, making it difficult for vintage owners to enjoy them as they looked when new (bracelets invariably break, lose links, etc.).
The tear-drop case (-6060) and the sloping tear drop (-6070) are two other smaller case styles. For example:
The -6070 style is especially unique in that it is the only one I have seen that has a dial with Arabic numbers or a dial without a jewel count. The -70xx styles are in the 38mm size range, such as this -7002, and have broader (and wider) lugs than the -601x style cases:
I have also noticed that the size and shape of the lugs reflect the dates of manufacture. Here is a rare Business Bell whose lugs are just a bit smaller:
The lugs aren't as wide as the -700x but aren't as slim as the -702x style. But note how some -702x style cases have much slimmer lugs, particularly on the oldest examples:
If you closely examine the -702x style above, you will see subtle differences. On some the lugs curve smoothly, while on others there is an obvious angle to the curve. This is most obvious if you compare the -7000 to the -7001. The same can also be observed on -601x style cases.
The variety of case styles and combinations of case and dial and bezel mean that being a Bell-Maniac means never having to say you've got 'em all.
