  Dusty star-forming galaxies (DSFGs) contribute significantly to the stellar
buildup at cosmic noon. Major mergers and gas accretion are often invoked to
explain DSFGs' prodigious star-formation rates (SFRs) and large stellar masses.
We conducted a spatially-resolved morphological analysis of the rest-frame
UV/NIR emission in three DSFGs at z~2.5. Initially discovered as CO emitters by
NOEMA observations of a bright Herschel source, we observed them with the
JWST/NIRCam as part of the PEARLS program. The NIRCam data reveal the galaxies'
stellar population and dust distribution on scales of 250 pc. Spatial
variations in stellar mass, SFR, and dust extinction are determined in resolved
maps obtained through pixel-based SED fitting. The CO emitters are massive,
dusty starburst galaxies with SFRs ranging from 340 to 2500 Msun/yr,
positioning them among the most active SFGs at 2<z<3. Notably, they belong to
the ~1.5% of the entire JWST population with extremely red colors. Their
morphologies are disk-like, with effective radii of 2.0-4.4 kpc, and exhibit
sub-structures such as clumps and spiral arms. The galaxies have dust
extinctions up to Av=5-7 mag with asymmetric distributions extending over
several kpc and including off-center regions resembling bent spiral arms and
clumps. The NIR dust-attenuation curve in these sources deviates from standard
laws, implying different dust grain properties than commonly assumed in
starburst galaxies. The proximity of galaxies with consistent redshifts, strong
color gradients, overall disturbed appearance, asymmetric dust obscuration, and
wide-spread star formation favor interactions (minor mergers and flybys) as the
mechanism driving the CO galaxies' exceptional SFRs. Their large masses and
rich environment hint at membership in two proto-structures, as initially
inferred from their association with a Planck-selected high-z source.
