In baseball and hockey (sports I know), Donruss did this with insert sets where the first x were die cut, and the rest were not. So say we had a SN100 card, where the first 15 were die cut. We listed them as separate sets, the die cut got SN100, PR15, the non-die cut one would get SN100, PR85 (and in the release notes we would put a blurb about which serial numbers would be found with each).
This does sound a bit different, but if each card variation is listed individually, the same can be done here. SN to the full number, and a PR for the actual number of cards issued. Note2 would be a good place to mention that one variation is the first 25 SNed and the other one is the last 100 SNed. (Or it can be stated "SNs 1-25" and "SNs 26-125" - whatever you think works best.)
-- Dan --
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