The Vinča symbol corpus of Neolithic southeastern Europe and the Indus script of the Harappan civilization are among the most prominent undeciphered sign systems of the ancient world. Despite extensive cataloging of both corpora, direct structural comparison between the two symbol inventories has received relatively limited systematic attention. This working paper presents preliminary observations indicating the presence of multiple morphological correspondences between Vinča signs and Indus script symbols. Several compound signs appear nearly identical or structurally similar across the two corpora, including configurations involving enclosed elements, internal modifiers, and composite geometric constructions. In addition to these graphical correspondences, the study proposes a structural framework for understanding the internal organization of Indus inscriptions. Evidence suggests that many inscriptions may be organized around paired-base formations, in which two independently attested primary symbols function together as the dominant structural unit within the sequence. Alongside these formations, a second category of modified-base constructions appears in which a primary sign is accompanied by smaller modifying elements that refine or qualify its meaning. Some of these modifying elements also occur independently elsewhere in the corpus, indicating that the script may contain polyfunctional graphemes capable of operating both as independent signs and as dependent modifiers. Preliminary examination of sign distribution patterns further suggests that certain modifiers exhibit restricted positional behavior within inscriptions, appearing primarily adjacent to base signs rather than in initial positions. This pattern is structurally consistent with writing systems in which dependent elements function analogously to vowel markers or reduced syllabic components, while the dominant base signs encode primary lexical or semantic units. Under this interpretation, Indus inscriptions may combine compound base pairings with internally modified graphemes, producing a layered compositional structure. The analysis further demonstrates that comparable compound configurations can be produced through the recombination of independently occurring Vinča symbols, suggesting that both traditions employ similar principles of graphic composition. The purpose of this paper is not to propose a definitive historical relationship between the two systems but to document these structural correspondences and to introduce a compositional model in which paired base signs and dependent modifiers operate together to generate meaning within the inscriptional sequence. These observations encourage further quantitative and contextual analysis of the structural organization of early Eurasian symbolic traditions.