Electron nuclear double resonance (ENDOR) studies were carried out over a range of temperatures for five different preparations of polyacetylenes (PAs): Shirakawa (trans-PA), Shirakawa (cis-PA), Durham PA, Naarmann PA, and "enolic PA". EPR and magnetic susceptibility (SQUID) measurements were also performed and correlated with ENDOR measurements. Whereas the same quasi-delocalized paramagnetic defect ("soliton") appears to give rise to the ENDOR spectra for all preparations, the extent and dynamics of the soliton defect vary significantly with different preparations illustrating the importance of the lattice (cross-links, residual catalyst, elimination products, adjacent polyene chains, etc.) surrounding and terminating a soliton in defining apparent delocalization of the observed soliton. The analysis of the temperature dependence of ENDOR spectra is complicated by the relatively high concentration of paramagnetic solitons, which may facilitate exchange narrowing of ENDOR spectra. The ambiguity of whether spectral narrowing with increasing temperature arises from exchange interactions (spin diffusion) or from modulation of hyperfine interactions by soliton diffusion (real translational diffusion) cannot be resolved by the analysis of ENDOR spectra. The ENDOR spectra of enolic polyacetylene is unique in reflecting hyperfine interactions of only one sign compared to other forms of polyacetylene, which exhibit features associated with both positive and negative hyperfine interactions. The spectra of the enolic form suggest a restriction of the soliton to one side of the polyacetylene chain (centered on carbons containing protons but not on a carbons containing oxygen), i.e., removal of the degeneracy of the normally degenerate two solitons that can exist on either sides of a polyacetylene chain.