I appreciate any kind of comments.
If you are going to consider 1/4 points in your guaging, and are a stamp collector, consider making up a Vario page with known perforation guaged stamps, they can be any country, as long as they are clean, crisp perforations.
Have them face down and write on the back the Guage as identified.
Then, when you come across dodgy, worn, badly perforated examples,
it becomes a peace of mind to use your vario page of perforations as an accurate guide to match to.
It is a simple, but trustworthy method of guaging, that overcomes bent perf pin examples etc.
Take into consideration as well, some catalogues only guage to the 1/2 a tooth.
Australia Sc#415 1966 $1 Mathew Flinders
Sc#415 14.5 x 14 $2
Sc#415a 15x14 $110
Keeping a used common stamp of the 14.5 x 15 in the vario page
is a simple fast, efficient way to identify the Valuable variable.
Personally, I distrust all these new fandangled digital Perf ID's.