The cab that I built for my pt isn't like the ones that you built , the 425 doesn't have the room between the hood and the back of the seat. I made the roof out of metal and a metal frame of about 1 inch square tubing. I bent the tubing so that it was wide up to the top for the canopy and to accommodate my shoulders and tapered inward toward the bottom to match up with the tub. I made the doors to swing open like suicide doors, and made them so that they were easy to take off and to put on. The windshield I made so that the top is out a little farther than the bottom of the window, which it seems to keep rain from getting on the windshield bad enough to have to use wipers, which at this time I don't have any on it but intend on someday doing if I ever see that I need to. I used plexiglass for the windows so I was able to bend it to match the contours of the frame. I have near total visibility all the way around it. I bought a small electric heater for mine also that I could plug into a 12 volt plug in, but like you I have found it unnecessary to use no colder than it has got for the last several years around here but just in case I need it I have it. I made mine light so that it is easy to take off and put on by myself. I still have several things that I intended to do to it , but it works well the way it is so I have neglected to finish it the way I planned to. The last couple of years I have only took the doors off during the summer, but it won't be too much longer that I'll have to get the doors back out and put on. I am almost computer illiterate or I would post pictures of it. My son is a computer software engineer but as of right now I don't have the desire to learn about computers, too much other stuff going on right now I guess. I showed pictures of it to Tractor Doc when I went toget the finish mower that he had for sell.