Thunderjets were fitted with several versions of two canopies. The canopies fitted to the XP-84 through F-84D were 8 inches shorter, and the canopy frames were 12 inches shorter, than those fitted to the E- and G-models. Also, the tendancy for the canopies to blow out during flight lead to fitting the G-models with white fiberglass tape braces applied to the outside of the canopy. As this fix solved the blowout problem, the braces were retrofitted to other aircraft in service. The other change to the canopy was the addition of an access plug at the right rear of the canopy which enabled maintainance crews easier access to the equipment on the rear deck of the canopy. The photos here are to show the difference in canopy length, which is much more obvious on canopies where the canopy braces have been installed.
Early canopy as fitted to XP-84 through F-84D, and with bracing added. Two features are clearly evident to distinguish the early canopy from the late. One is the distance between the second and third canopy braces, which is 11 inches on the early, and 19 inches on the late. The other is the taper at the rear of the canopy frame, which accounts for another 4 of the 7 inches of the 15 inches added to the fuselage length.
This is not a factory canopy. Rather, it is the front part of an early canopy butted to the back part of a late canopy. It shows distinctly the two "third" braces and the 8 inch difference in length of the early and late canopies. Notice also that the late canopy frame has the added "fillet" panel at the extreme back, and which panel is not present on the early canopy frames. The other 3 inches of the 15 inch extension were accommodated by a "plug" panel aft of the canopy frame. See Fuselage Extension page.
I have built models of the early and late Thunderjets with the short and long canopies respectively. My pages of photos of these models includes a page comparing the difference in canopy lengths.