Randall,
I assume that you really do mean the "sear safety" and not the "sear bar". The sear asfety is the little spring on top of the sear and sideplate with a projection downward thru the top of the sideplate. One is pictured below. These were only installed on Police Lugers. Does your gun have any letters & numbers stamped into the front grip strap? If this is what you are refering to, it is not supposed to come off, and if it does come off easily, I would remove it before firing the gun. If you loose it you will have a VERY HARD time finding another one.
If you decide to send the grips to me for recheckering, please do not clean them! The cleaning process makes the top of the wood "fuzzy" and more difficult to checker.
http://boards.rennlist.com/upload/policeluger.jpg