1985 380sl oil gage & leak
 

I have an oil leak somewhere in my 1985 380sl (120,000 miles)....When I stared it up today , I noticed that my oil gage needle kept dropping

between 2 1/2 & 1 1/2..I know that I am a little low on oil, so could this be due to being low on oil...also, if you have an oil leak, where is it most likely coming from? Thanks!