@JohnnyC
The part numbers for the two market versions (RHD vs LHD) indicate 3 generations of these split window frames, each with slighty different part numbers. The latest shown production date ended in September 1977, as does the end of production of the 2 versions (RHD vs LHD) of the TNK individual wiper motors they used. If I had to hazard a guess, perhaps the final generation: LHD 56301-90323 and RHD 56301-90322, may have had the built-in defrost openings. The Pakistan army may have ordered theirs during the first two generations which perhaps did not have defrost openings, and the Venezuelan army frame I procured with the defrost openings may have come later--from the final generation. All of the split frames I have seen in various Mud postings seem to have originated from and been exported used from Pakistan. I have one of these that was brought back by a US military contractor.
The factory parts catalog shows the standard one-pane windshield frame pictured with the bottom weatherstrip showing defrost openings; the split-windshield frame is not shown with the same weatherstrip. Could be due to the date the illustrations were created to span multiple years of production. BTW I have seen references to a "Tropical" windshield frame, of which I have no idea.
Regardless, the practical utility of these oddities leaves much to be desired, from the "impaler" brackets to the whistling and leaking weatherstripping. But as said before, the "coolness factor" overrides the frustration, much as do the slow, unsynchronized single wiper motors, the squeegee wiper blades, the tractor engines, and the myriad hard-to-find bits and bobs some of us constantly search the market for.
Oh, and thanks for responding--6 years later. Hmmmmm. Good fun !!
Cheers.
