Hi Jaxom 100 --
In the process of plating some stamps yesterday -- I noticed that the first of the two StampSmarter copies currently slotted as position 58L4 is not correct. More specifically, the stamp in the "number 1" slot with the bluish-black JULY 15 cds cancel is actually position 13L4 -- (a copy of which is below to avoid any possibility of confusion).
I also noticed that this is the same stamp slotted as 58L4-(NOT) in your Plate 4 compression chart -- so you will probably want to correct both the StampSmarter database and the compression chart accordingly.
As an abundance of caution -- I re-confirmed that the second stamp slotted as 58L4 on StampSmarter is, in fact, correctly plated -- so you could easily use that copy as the replacement for your compression chart. More specifically, the stamp in the "number 2" slot is the copy with the indistinct black MMM 27 cds cancel -- and for which a scan is also posted below to avoid any possibility of confusion.
As an aside -- based on my experience, the utilization of compressed images -- while a very powerful plating aid -- also has its limitations.
For example -- compressed images can be significantly distorted (and thus misleading) if the frame lines of the stamp in the original source scan are not as close to horizontal or vertical as possible before compression (i.e., perfectly aligned on the "X / Y axis"). More significantly, if the stamp was torn, or not flat on the scanner, or if there were bends in the paper when scanned, frame line curves can be distorted (or artificially introduced) on the compressed image that are not true to the position. In other words -- if the stamp in the original source scan is tilted at an angle -- or has any paper bends, creases, or tears -- or is not perfectly flat on the scanner for any other reason -- the resulting compressed image will be distorted for purposes of comparability with other patient stamps from the same plate position -- and consequently, potentially misleading.
One final comment about Relief-A stamps on plate 4 where there are no recut varieties or other stand-out features -- many of these positions are very similar to each other -- and in my experience, while compressed images can be used as a powerful tool to help in narrowing down a short list of candidates -- they should not be relied upon in finalizing a plate position.
Regards // ioagoa
The following stamp is not 58L4 -- but is actually 13L4
The following stamp has been re-confirmed as 58L4