Hi Nicholas,
Your right these do not walk, though saved output shows it ends at DISMAN-EVENT-MIB. No walk for ACCELERATED, but worse the OIDs themselves show either " " or for signal strength I get -1.
Loading the MIB in ManageEngine's MibBrowser I get error that it could not parse the file: "Couldn't resolve these sequence constructs: {modemEntry]. Every other MIB provided from the zip does load, just not ACCELERATED-MIB.