I think the most important thing is keeping the style consistent for sorting, even if they are a bit inconsistent in how they print the number on the obi. I don't think the hyphen is necessary if it's not routinely used, but to be consistent all of the LC* or LWEX* albums would need to be edited.
Looking on my shelf, some NACL, AZCA, KICA (King Records distribution) and SVWC don't use the hyphen on the Obi either. In general though, most catalog numbers have a stem and a number. An argument can also be made that rest of the number -- spaces, dashes -- is just stylistic. There is evidence that what's printed on the case is not always how it appears in a company's other literature.
KICA should keep its hyphen because King Records
considers catalog numbers to have hyphens. I think that may be the case with most of these companies. LWEX and LC could be exceptions, but it will take some investigating to find out. Note also that, if
most other sites use a different form of the catalog numbers, whether that be hyphenated or not, then our album pages won't come up in the searches, unless we start listing permutations of catalog numbers.