Finally..... Antenna installed...Just to conclude this original posted thread for those that may have simular issue of installaling antenna....
As Bob from Dodgeb4ya had mentioned about removing mast from base:
At first it looked as though the mast did not come out, (I had an original older used antenna that I was trying to put in my car though), but I did remove the bottom mast screw which aparently was used to hold the chrome mast and a stopper into base. At first the mast didn't move from base, so I sprayed WD40 at both ends between mast and base and let stand for a few days, sprayed again inbetween. After a few days, the mast slid right out. Wala ...done deal... I placed base loosly on inside with all hardware on, then slid the chrome mast down into base hole, used a stubby screw driver and reinstalled screw with stopper onto bottom of mast.
I secured outer mounting nut keeping antenna straight as posible. Then screwed in all inside mounting screws to base and car, all fit into the original holes, which was nice. Well there you have it....Good luck to anyone else that may have same problem....Thanks Bob.
Ron