Cover Screws for Trico Vacuum Wipers

[eystein]

I have noticed that there are two versions of the screws holding the top lid to the bowl on the Trico vacuum wipers. I have studied the top cover screws on some original TR-C1 wipers. The “top hat" portion of those screws is almost the same diameter as that of the widest portion of the screw. On the other hand, the other type of screw has a smaller head, making the widest portion of the screw stick out like a brim of the hat. I have seen this latter type of screw only on the replacement style (TCX-) wipers. The attached photos show the screws from the original TR-C1 on the left and the screw from the TCX-1 replacement style wiper on the right. Now was the screw on the left only used for the TR-C1 or was it used for all original Tr- series wipers ?

Can anybody chime in with experience/pictures from original, unrestored Trico vacuum wipers ?

I think there are two main questions that could be answered :
1. Can we say with reasonable certainty that the original TR-C1 Wiper (Used on most straight windshield Closed cars and the Cabriolet) had the wide screws shown on the left ?
2. If so, can we generalize to say that all original wipers ( e.g. TR-O1 (Roadster, Phaeton), TR-C2- (Slant Windshields)) had the screws on the left, or were they exclusive to the TR-C1 ?
3. Were the screws shown on the right in my photo only used on the later replacement wipers ?

For information, how to distinguish an original from a replacement wiper :
- The original TR- series wipers had deep front covers fastened with two #3-48 round head screws
- The replacement TCX- series wipers had a shallow front cover pressed on to the wiper body without screws, and had a hump on the top of the vacuum intake.