What about this? Not perfect, but it might give you an idea how to access the hidden DBNavigator buttons. For example, you could replace the glyphs by your own bitmaps in a similar way.
type
TMyDBNavigator = class(TDBNavigator)
end;
procedure ChangeNavButton(ANavigator:TDBNavigator; ABtn:TDBNavButtontype; ASymbol:string);
begin
with TMyDBNavigator(ANavigator).Buttons[ABtn] do begin
Glyph := nil;
Caption := ASymbol;
Font.Style := [fsBold];
end;
end;
{ TForm1 }
procedure TForm1.FormCreate(Sender: TObject);
begin
ChangeNavButton(DBNavigator1, nbPrior, ' < ');
ChangeNavButton(DBNavigator1, nbNext, ' > ');
ChangeNavButton(DBNavigator1, nbFirst, ' |« ');
ChangeNavButton(DBNavigator1, nbLast, ' »| ');
end;