  The existence of a vast nova shell surrounding the prototypical dwarf nova Z
Camelopardalis (Z Cam) proves that some old novae undergo metamorphosis to
appear as dwarf novae thousands of years after a nova eruption. The expansion
rates of ancient nova shells offer a way to constrain both the time between
nova eruptions and the time for post-nova mass transfer rates to decrease
significantly, simultaneously testing nova thermonuclear runaway models and
hibernation theory. Previous limits on the expansion rate of part of the Z Cam
shell constrain the inter-eruption time between Z Cam nova events to be $>$
1300 years. Deeper narrow-band imaging of the ejecta of Z Cam with the Condor
Array Telescope now reveals very low surface brightness areas of the remainder
of the shell. A second, even fainter shell is also detected, concentric with
and nearly three times the size of the "inner" shell. This is the first
observational support of the prediction that concentric shells must surround
the frequently-erupting novae of relatively massive white dwarfs. The Condor
images extend our Z Cam imaging baseline to 15 years, yielding the inner
shell's expansion rate as $v = 83 \pm 37$ km s$^{-1}$ at 23 degrees South of
West, in excellent agreement with our 2012 prediction. This velocity
corresponds to an approximate age of $t = 2672^{-817}_{+2102}$ yr. While
consistent with the suggestion that the most recent nova eruption of Z Cam was
the transient recorded by Chinese Imperial astrologers in the year 77 BCE, the
age uncertainty is still too large to support or disprove a connection with Z
Cam.
