  We present high resolution (9$^{\prime \prime}$) imaging of the
Sunyaev-Zel'dovich Effect (SZE) toward two massive galaxy clusters, MACS
J0647.7+7015 ($z=0.591$) and MACS J1206.2-0847 ($z=0.439$). We compare these 90
GHz measurements, taken with the MUSTANG receiver on the Green Bank Telescope,
with generalized Navarro-Frenk-White (gNFW) models derived from Bolocam 140 GHz
SZE data as well as maps of the thermal gas derived from {\it Chandra} X-ray
observations. For MACS J0647.7+7015, we find a gNFW profile with core slope
parameter $\gamma= 0.9$ fits the MUSTANG image with $\chi^{2}_{red}=1.005$ and
probability to exceed (PTE) = 0.34. For MACS J1206.2-0847, we find
$\gamma=0.7$, $\chi^{2}_{red}=0.993$, and PTE = 0.70. In addition, we find a
significant ($>$3-$\sigma$) residual SZE feature in MACS J1206.2-0847
coincident with a group of galaxies identified in VLT data and filamentary
structure found in a weak-lensing mass reconstruction. We suggest the detected
sub-structure may be the SZE decrement from a low mass foreground group or an
infalling group. GMRT measurements at 610 MHz reveal diffuse extended radio
emission to the west, which we posit is either an AGN-driven radio lobe, a
bubble expanding away from disturbed gas associated with the SZE signal, or a
bubble detached and perhaps re-accelerated by sloshing within the cluster.
Using the spectroscopic redshifts available, we find evidence for a foreground
($z=0.423$) or infalling group, coincident with the residual SZE feature.
