  We have investigated the MeV behaviour of the \gray blazars 3C~454.3 and CTA
102 by analyzing all COMPTEL observations of this sky region during the
complete CGRO mission. Both sources are detected by COMPTEL at the upper
COMPTEL energies; although their flux estimates may be uncertain by possible
minor contribution of nearby unidentified EGRET \gray sources. While CTA 102
was only detected at energies above 10 MeV during the early mission, 3C~454.3
is most significantly detected in the COMPTEL 3-10 MeV band in the sum of all
data. Time-resolved analyses indicate a weak (near COMPTEL threshold) but
likely steady 3-10 MeV emission over years, being independent of the observed
time variability at energies above 100 MeV as observed by EGRET. This
energy-dependent variability behaviour suggests different emission mechanisms
at work at the two bands. Putting the COMPTEL fluxes in multifrequency
perspective (radio to \grays), reveals for both sources the typical two-hump
blazar spectra, with a low-energy maximum around the IR and a high-energy
maximum at MeV energies. The latter one dominates the energy output across the
whole electro-magnetic spectrum. The results of our analyses are discussed in
the framework of current blazar modeling.
