Got a mongoose frame serial number m3-e2519. I found out it is a 83, but could be a supergoose, expert or california. it has the two holes in the drop outs which could be any, i might be wrong. any help would be cool as. Found out the frame was used on a few, mine has the tapered forks. If it could be one of many which is the coolest to do. Any helps good. P.s sorry for posting in wrong places new to this.