Rod, I had some new weatherstrip on hand from the previous owner but the drivers side didnt make it through the second "uninstall" so Im ordering a new set from RIKS.  I think they have the latex stripping which is more flexible and more like the original.  Ill be ordering it tomorrow morning and usually get my orders the following day from them.  I highly recommend them to anyone needing parts, AND they are a forum supporting vendor.

When I did mine I found a fully trained monkey to help.........oh wait, no that was my son.
 I was going to mention what Dan offered. Putting masking tape every 12" or so does really help. I did have to go back later and put a little more adhesive in places where it was too thin. But I feel better too thin than too much. "T"

Well guys, you've just talked me out of my next project--new weatherstrip for the t-tops.  Maybe I'll just drive on dry days!!!

Jim, I am sure it is a project that you can do, just trying to get as much information from those that have done it so it is a job we can address without encountering the problems others have. Thats what this site is all about, getting the help and knowledge so we can do these things. And let me just say its the best site around to gain the information needed! So go ahead and tackle that job! the help is here for you.
Rodney

I use a acid brush,one made for solder flux, do a couple inches at a time, you will learn to be patient after you get over being mad   lol

Jim

I have a 82 so the t-top weatherstripping could be different but mind did not take adhesive.  It is push in with those plastic pins.  The 69 and up use the plastic pins if the catalog pictures are to be believed  I just not seen any pictures of 68 weatherstripping for the T-tops. 

I'm thinking yours may not use adhesive either.  Anyway if it is plastic pins and not adhesive it is an easy job.  Done it twice.  One my car and helped a guy do his.  Both were later models than yours.

The set I got work great.  I had my car out in a hard SoCal rain.  That is different that most of you get but it was coming down good.  Had to go to church and it is my daily driver.  Which means I would rather drive it than the Toyota or Cadillac.  I was really surprised that no rain came in from under the T-tops.  Fastest I got was 50mph which is ok but not the 75mph I do no the freeways and it may be different at that speed.  I got my weatherstripping from Mid America Motorworks.