Thank y'all for posting answers. For sure I am agreeing with you guys about doing putty zim since the old kit was only $7 so I have nothing to loose. If it goes wrong, I can always sand and try again...
I did some research here and understand that modelers like to use 3M BLUE Acrylic Glazing Putty because it doesn't dry quickly and it comes in a huge tube lasting forever which is much cheaper than Milliput. After visiting couple of auto shops today, I finally found one but it wasn't BLUE and it was WHITE. The guy told me its pretty similar and it doesn't dry quickly like its sisters Green and Red. He allowed me to look at the computer monitor and it said white is a good substitute for blue... hope he is being honest.
Have one of you tried this?
It was $17 at O'Reilly Auto Shop. Tube is HUGE...