search text in home page set to autocomplete=off, can I change this field only to autocomplete=on

On the about:home web page the search text field is set to autocomplete=off when I inspect the field element. I would like to change it to autocomplete=on on a permanent basis. I can do this on a session basis by editing the element details but I would like to be able to do this permanently. Is there a method by which this can be done? I would also need to remove the "searchSuggestionTable" references. My reason for requiring this is that I use the Forms History Control add-on. This allows a drop down of my own search history entries to be displayed rather than those from a search engine. Thanks for any suggestons.