Wine Indentification Help

have numerous series 1916 wine stamps that can be either rouletted 3.5 or 7. I have 4 that are pretty much imperf as shown below. is there another way to determine which it is? color between the two series seem the same. My first thought would be to use a dated cancel if it exits. since the rouletted 7 came in 1933 anything prior would be re22-52. this has no cancel.

when unable to determine do you just cat it as the cheaper of the 2?

Any thoughts or guidance would greatly be appreciated.

This stamp appears to be rouletted on the right side. A sharper larger scan might make it possible to see which gauge it is.

thanks Rev for the help. Here is a scan at 1200 and zoomed in. had to use optimizer to get it to fit. Thanks

I'm inclined to say 3.5 looking at this, but with 3 sides trimmed it's really only a spacefiller for a sound example.