There are still 4 coax cables that run from the LNB to the top of the turrent which you should check for continuity. There are also 4 cables inside the base that run from the top of the turret to the 4 outputs at the base of the antenna which can be checked. You can reverse the coaxes (a to b, b to c, c to d and d to a or similar) to see if a different satellite signal disappears. It seems strange that a bent reflector could drop 103 but be OK on 99. However, I had a customer with 99/103 issues and there were no visible indications of a reflector issue. Having replaced everything else including the receiver I replaced the reflector and it fixed everything.
As you mentioned, the reflector is not the regular DirecTV reflector so finding a random one to try won't help either and I believe the reflector costs about $90.
