You would need a template. There are basically only two straight edges on the thing, and there's no easy way to describe the angles/arcs on the front and top.
That’s what I’ve found. I’m making my second template but thought I’d see if someone knew the factory dimensions. The width across the top and also the bottom would be helpful. It’s the front edge that is the problem and that’s the arc/angle you mention
When my slant window A Victoria needed a new door glass I just drove the rod to the glass shop in my town. Picked it up the following day. Easy.
@alchemy x 2!! I can trace around a new door glass I had cut for my sedan if you want. PM your address. To save you the hell and expense I ran into doing mine: Make a template from my paper pattern to start. Install the front and rear runners/guides and felts. Slid the template in and sand to fit, and slide fully top to bottom. Mark R & L. Cut the new glass from the template. Mine were individually different R to L. Difference in the factory welded guides. One side would bind half way up. Sanded down one edge 1/16” and bingo.
Thanks for the offer. I made a second template out of Masonite and it fits nicely. I’ll have a local auto glass shop cut the glass for me. You are right about differences in the right and left doors. Nothing in these old cars are “standard”.