Just call any of the vintage glass vendors and order the glass. They have templates for all of the old cars. I'm sure there is one listed in the index on this site.
thanks for the non "smart ass" answer.( from the guys that have never done it.) its tough to get the window right with new felts, and how tight to get them
Not a smart ass answer..just trust my own measuring..like you should do you note that one answer here says his measure different from side to side?
Mine ended up with a slight taper so measure top bottom and middle, also the glass guy can grind narrower if it is to tight error on the tight side.
Don't know if this is any help but when I got round to getting the glass cut for my Model A Pickup I made templates out of plywood first. Fitted it just like the glass with all felts in place then checked it would roll up and down freely. Worked great.
I too made luan templates. Glass was cut to same size and very close to same thickness. Worked great with the new felt
..... exactly, no matter how experienced and well meaning a person on the internet may(or may not) be, so long as you understand what you are trying to do, figuring things out yourself isn't a bad thing.
Order it from Chris blattie here on the hamb He will ship a full set for just over 300 Best deal intown