Here are two top straps for the rear curtain. One is leather and the other fabric. Both are original Ford T items. What years are they for? I have had both of them for over 50 years. They are about 15 inches long (the leather or fabric potion.) The ring and buckle add length.
I know that cotton webbing is correct for 1917 model year based on cars with known histories from new. According to RV Anderson's catalog, webbing is correct for 1915 model year forward.
Bruce at: http://www.mtfca.com/encyclo/S-T.htm#top has:
Similar in style to 1916 but rear window now three separate pieces, each 9-1/2 x 5-1/4” with 3” between them. Sockets in early 1917 were oval in cross section but were changed to rectangular cross section by 1918. “Lift the Dot” fasteners replaced the Murphy type in some locations. The leather top support straps to the windshield were changed to cotton webbing, and the buckle-type hook now had a loop only for the strap. About 1920 the top was redesigned to include a “visor” above the windshield for a better weather seal.
However, I believe the MTFCI Judging Guidelines Sixth Edition under 1915 says:
305: Front strap was made form blackened leather and was attached to windshield at the hinge. Rear straps changed to cotton webbing in Dec 1914. Steel hardware was painted black.
For 1916 the added the rear straps were now cotton webbing.
Note -- there would have been some overlap while existing stock as well as orders that had been previously placed arrived with the older style straps.
Additionally I believe we have seen early photos of 1915 cars that had the cotton webbing for the front straps. This would be an area I believe we could help better document for both the Encyclopedia and the Judging Guideline. In general I believe the switch to the cotton webbing occurred earlier than what Bruce has in his on line encyclopedia. And I suspect the front web transitioned to the web belt prior to the 1916 model year. But how long was the overlap when both were used?
One well documented example is the transition to the single valve cover engine blocks. It began Nov 1, 1921 (ref: pg 526 Bruce's book "Model T Ford) and both styles were manufactured at the Highland Park Plant until Apr 3, 1922. So six months in that case. And I do not know when Ford of Canada switched or how long the overlap there was.
If anyone has early photos of the cars showing the cotton webbing straps 1915 or earlier or has the leather straps showing 1915 or later please let us know. Additionally if anyone has any other documentation -- we would appreciate you sharing it.
Hap l9l5 cut off
When did Ford go from the ring to the D-ring on the rear straps? Was it at the change from leather to webbing?