There were three base generations of the JACK HOWARD bows. 1st, the original gamemaster (66"); 2nd, the GAMEMASTER JET (66"), and 3rd the GAMEMASTER CLASSIC (64"). Yours is the original. i
Some collectors may put ome extra value on it, but as a shooter, it is still a fine bow. Even back then, Jack advertized it as the fastet hunting bow ever made. He kept that claim through his JET and CLASSIC models.
With an "E" in the serial number, I would say it is one of the last of the original GAMEMASTERs
If I were to take a guess,I would expect your bow to bring about $300.00, depending on who bids on it.
HOWEVER, you did not do yourself justice by listing it erroneously as a Howard Hill bow, even though you posted a correction. If I were you, I would close the auction and relist it correctly.
If you are not into archery, I can undertand you wanting to sell it. But being that it was your dad's bow, I would keep it.