Why not try contacting Zotz, and ask them if they can produce the same sheets in 1/48th? If they normally produce other decals in this scale, and are shown there's a market for the B-25 decals, they might just do it.
It's evident and understandable that they are taking advantage of a brand new, never done before in this scale, kit release, and filling a void for aftermarket decals in this instance, so if they can gain additional revenue on the back of this, and it fits their marketing and production plans, they might well be agreeable to the suggestion. After all, it's mainly a question of re-scaling the original art work, then the advertising.