From 1400 of these stamps, I selected 105 lightly and clearly dated specimens. Here are the scans. This is my first take at the thorough classification of Dario Bardi.
These are the totals for the papers.
I do not find any 1E5's even though I think I should.
1E1..8; 1E2..1; 1E3..10; 1E4..2
I have just learned from Dario Bardi that there are two types of NGR (longer grooves horizontally left to right, or vertical up and down); hence the additional letters added to NGR here.
I don't have enough NOPs to distinguish the two types (matte and shiny) mentioned in the publication by Dario Bardi.
NOP..1; 2C-H..5; 2C-V..4; CL2..2
I do not find the 1L1 Dario Bardi mentions with vertical lines. All of the 1L1 specimens I find are aligned with horizontal lines. The stamp I have previously referred to as 1L4 is either rare, or a variation of the 1L5. The 1L2 is a very common stamp, receiving heavy use in 1952.
1L1..13; 1L2..34; 1L3..6; 1L5..7
About the placement of RA in 1E's, only the 1E4 paper has a horizontal placement of the watermark. The other three (1E1, 1E2, and 1E4) have vertical placements. I seem to not agree with Dario Bardi because he has two vertical and two horizontal placements in his listing that is equivalent to my 1E's. I have yet to look at the 1E5's that Dario Bardi finds, and I have for the 25c value.