First off, E-Bay does not allow offers of handguns or ammo for sale.
I suggest you contact http://rockislandauction.com and give them a list of what is there. Look at their catalogs and see what other stuff like it has sold for.
From personal experience I recommend them without qualification. Depending on what's in the collection it may be worth the expense to send stuff to them for a full appraisal even if it is decided not to list with them.
Also, get a good attorney's advice on how to expense the costs of appraising and selling the collection, as it can save a lot in taxes and other fees.