Sorry, I added an 'S' where there shouldn't be. The site works fine. I can't paste a link so here it is typed in. He supplies the plastic cut to size for each table he makes. He does all kinds of custom works as well, such as custom photo etch brass to your specifications and even add alternatives to what you send him.
http://www.warmplastic.com
Yes, they are called canopies. They can be jettisoned and the rear crew do eject through them - just like the forward canopies. The weathered look is due to the clear canopy with the interior paper backing. The paper backing is scored with 1" circles throughout its surface. Sunlight sneaks through these scorings. The whole reason for the paper is direct sunlight completely obliterates the view-ability of the rear crew display monitors.
Hope this typed in link works. A 1/48 scale commission build I did for a squadron-mate. note the aft canopies.
http://s676.photobucket.com/user/Tracy_Mann/media/Aircraft/Vikings/48scaleViking2.jpg.html?sort=3&o=2
When you do the scribing for your forward canopy frame, you'll find 2 'D' shaped panels in the frame on either side of the refueling door panel. These are spring loaded retractable hand hold covers for the Plane Captains to use as the climb the non-skid covered avionics doors you explained earlier. They hold on to those while they polish the windscreens and canopies.
Tracy